Chemical: Drug
phenytoin

Available Guidelines

  1. CPIC Guideline for phenytoin and CYP2C9,HLA-B
  2. DPWG Guideline for phenytoin and CYP2C9

last updated 02/03/2015

1. CPIC Guideline for phenytoin and CYP2C9,HLA-B

Summary

Phenytoin is contraindicated in individuals with the HLA-B*15:02 variant allele ("HLA-B*15:02-positive") due to significantly increased risk of phenytoin-induced cutaneous adverse reactions of Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). Additionally, patients with the CYP2C9 poor metabolizer phenotype may require reduced doses of phenytoin.

Annotation

November 2014

Accepted article preview online August 2014; Advance online publication September 2014

  • Guidelines regarding the use of pharmacogenomic tests in dosing for phenytoin have been published in Clinical Pharmacology and Therapeutics by the Clinical Pharmacogenetics Implementation Consortium (CPIC).
  • Excerpt from the 2014 phenytoin dosing guidelines:
    • "[A]t least a 25% reduction of the recommended starting maintenance dose may be considered for CYP2C9 intermediate metabolizers with subsequent maintenance doses adjusted based on therapeutic drug monitoring and response. For CYP2C9 poor metabolizers, consider at least a 50% reduction of starting maintenance dose with subsequent maintenance doses adjusted based on therapeutic drug monitoring or response."
    • "[R]egardless of the CYP2C9 genotype and individual's ancestry or age, if the HLA-B*15:02 test result is positive, the recommendation is to consider using an anticonvulsant other than carbamazepine and phenytoin unless the benefits of treating the underlying disease clearly outweigh the risks... Alternative medications such as oxcarbazepine, eslicarbazepine acetate, and lamotrigine have some evidence linking SJS/TEN with the HLA-B*15:02 allele and thus caution should be used in choosing alternatives to phenytoin."
  • Download and read:

Table 1: Phenytoin/fosphenytoin therapy recommendations based on HLA-B and CYP2C9 phenotype/genotype

Adapted from Tables 1 and 2 of the 2014 guideline manuscript.

  • HLA-B*15:02 "positive": 1 or 2 *15:02 alleles
  • HLA-B*15:02 "negative": No HLA-B*15:02 alleles reported
CYP2C9 PhenotypeCYP2C9 genotypeHLA-B*15:02 "positive" - ImplicationsHLA-B*15:02 "positive" - Therapeutic recommendationHLA-B*15:02 "positive" - Classification of recommendationHLA-B*15:02 "negative"- ImplicationsHLA-B*15:02 "negative"-Therapeutic recommendationHLA-B*15:02 "negative"-Classification of Recommendation
CYP2C9 Extensive MetabolizerNormal activity ~91% of patients; An individual carrying 2 normal activity alleles; Example diplotype:*1/*1Increased risk of phenytoin-induced SJS/TENIf patient is phenytoin-naive b, do not use phenytoin/fosphenytoin.STRONGNormal phenytoin metabolismInitiate therapy with recommended maintenance dose d.STRONG
CYP2C9 Intermediate MetabolizerHeterozygote ~8% of patients; An individual carrying one normal activity allele plus one decreased function allele; Example diplotypes: *1/*3, *1/*2Increased risk of phenytoin-induced SJS/TENIf patient is phenytoin-naive b, do not use phenytoin/fosphenytoin.STRONGReduced phenytoin metabolism, higher plasma concentrations will increase probability of toxicities.Consider 25% reduction of recommended starting maintenance dose d. Subsequent doses should be adjusted according to therapeutic drug monitoring and response.MODERATE
CYP2C9 Poor MetabolizerHomozygous variant ~1% of patients; An individual carrying 2 decreased function alleles; Example diplotypes: *2/*2, *3/*3, *2/*3Increased risk of phenytoin-induced SJS/TEN.If patient is phenytoin-naive b, do not use phenytoin/fosphenytoin.STRONGReduced phenytoin metabolism, higher plasma concentrations will increase probability of toxicities.Consider 50% reduction of recommended starting maintenance dose d. Subsequent maintenance doses should be adjusted according to therapeutic drug monitoring and response.STRONG

b If the patient has previously used phenytoin for longer than 3 months without incidence of cutaneous adverse reactions, reinitiate phenytoin with caution. Adjust dose based on CYP2C9 genotype if known.


last updated 02/07/2014

2. DPWG Guideline for phenytoin and CYP2C9

Summary

Use the standard starting dose of phenytoin and reduce the maintenance dose based on CYP2C9 genotype; monitor response and serum concentrations and be aware of ADEs.

Annotation

The Royal Dutch Pharmacists Association - Pharmacogenetics Working Group has evaluated therapeutic dose recommendations for phenytoin based on CYP2C9 genotype [Article:21412232].

Genotype Therapeutic Dose Recommendation Level of Evidence Clinical Relevance
CYP2C9 *1/*2 Standard loading dose. Reduce maintenance dose by 25%. Evaluate response and serum concentration after 7-10 days. Be alert to ADEs (e.g., ataxia, nystagmus, dysarthria, sedation) Published controlled studies of good quality* relating to phenotyped and/or genotyped patients or healthy volunteers, and having relevant pharmacokinetic or clinical endpoints. Minor clinical effect (S): QTc prolongation (<450 ms females, <470 ms males); INR increase < 4.5Kinetic effect (S)
CYP2C9 *2/*2 Standard loading dose. Reduce maintenance dose by 50%. Evaluate response and serum concentration after 7-10 days. Be alert to ADEs (e.g., ataxia, nystagmus, dysarthria, sedation) Published controlled studies of good quality* relating to phenotyped and/or genotyped patients or healthy volunteers, and having relevant pharmacokinetic or clinical endpoints. Minor clinical effect (S): QTc prolongation (<450 ms females, <470 ms males); INR increase < 4.5Kinetic effect (S)
CYP2C9 *1/*3 Standard loading dose. Reduce maintenance dose by 25%. Evaluate response and serum concentration after 7-10 days. Be alert to ADEs (e.g., ataxia, nystagmus, dysarthria, sedation) Published controlled studies of good quality* relating to phenotyped and/or genotyped patients or healthy volunteers, and having relevant pharmacokinetic or clinical endpoints. Clinical effect (S): long-standing discomfort (> 168 hr), permanent symptom or invalidating injury e.g. failure of prophylaxis of atrial fibrillation; venous thromboembolism; decreased effect of clopidogrel on inhibition of platelet aggregation; ADE resulting from increased bioavailability of phenytoin; INR > 6.0; neutropenia 0.5-1.0x10{^}9^/l; leucopenia 1.0-2.0x10{^}9^/l; thrombocytopenia 25-50x10{^}9^/l; severe diarrhea
CYP2C9 *2/*3 Standard loading dose. Reduce maintenance dose by 50%. Evaluate response and serum concentration after 7-10 days. Be alert to ADEs (e.g., ataxia, nystagmus, dysarthria, sedation) Published controlled studies of good quality* relating to phenotyped and/or genotyped patients or healthy volunteers, and having relevant pharmacokinetic or clinical endpoints. Minor clinical effect (S): QTc prolongation (<450 ms females, <470 ms males); INR increase < 4.5Kinetic effect (S)
CYP2C9 *3/*3 Standard loading dose. Reduce maintenance dose by 50%. Evaluate response and serum concentration after 7-10 days. Be alert to ADEs (e.g., ataxia, nystagmus, dysarthria, sedation) Published controlled studies of good quality* relating to phenotyped and/or genotyped patients or healthy volunteers, and having relevant pharmacokinetic or clinical endpoints. Clinical effect (S): long-standing discomfort (> 168 hr), permanent symptom or invalidating injury e.g. failure of prophylaxis of atrial fibrillation; venous thromboembolism; decreased effect of clopidogrel on inhibition of platelet aggregation; ADE resulting from increased bioavailability of phenytoin; INR > 6.0; neutropenia 0.5-1.0x10{^}9^/l; leucopenia 1.0-2.0x10{^}9^/l; thrombocytopenia 25-50x10{^}9^/l; severe diarrhea


Annotated Labels

  1. FDA Label for phenytoin and HLA-B
  2. HCSC Label for phenytoin and HLA-B

last updated 10/25/2013

1. FDA Label for phenytoin and HLA-B

Actionable PGx

Summary

A strong association between the risk of developing SJS/TEN and the presence of HLA-B*1502, an inherited allelic variant of the HLA B gene, in patients using carbamazepine. Limited evidence suggests that HLAB*1502 may be a risk factor for the development of SJS/TEN in patients of Asian ancestry taking other antiepileptic drugs associated with SJS/TEN, including phenytoin. Consideration should be given to avoiding phenytoin as an alternative for carbamazepine in patients positive for HLA-B*1502.

Annotation

Phenytoin sodium is an antiepileptic drug.

Excerpt from the phenytoin sodium (Dilantin) drug label:

There may be wide interpatient variability in phenytoin serum levels with equivalent dosages. Patients with unusually low levels may be noncompliant or hypermetabolizers of phenytoin. Unusually high levels result from liver disease, variant CYP2C9 and CYP2C19 alleles, or drug interactions which result
in metabolic interference.

Phenytoin is metabolized by hepatic cytochrome P450 enzymes CYP2C9 and CYP2C19, and is particularly susceptible to inhibitory drug interactions because it is subject to saturable metabolism. Inhibition of metabolism may produce significant increases in circulating phenytoin concentrations and enhance the risk of drug toxicity. Phenytoin is a potent inducer of hepatic drug-metabolizing enzymes. Serum level determinations for phenytoin are especially helpful when possible drug interactions are suspected.

Studies in patients of Chinese ancestry have found a strong association between the risk of developing SJS/TEN and the presence of HLA-B*1502, an inherited allelic variant of the HLA B gene, in patients using carbamazepine. Limited evidence suggests that HLAB*1502 may be a risk factor for the development of SJS/TEN in patients of Asian ancestry taking other antiepileptic drugs associated with SJS/TEN, including phenytoin. Consideration should be given to avoiding phenytoin as an alternative for carbamazepine in patients positive for HLA-B*1502.

For the complete drug label text with sections containing pharmacogenetic information highlighted, see the Phenytoin sodium (Dilantin) drug label.

*Disclaimer: The contents of this page have not been endorsed by the FDA and are the sole responsibility of PharmGKB.

Full label available at DailyMed

Genes and/or phenotypes found in this label

  • Congenital Abnormalities
    • Warnings section
    • source: PHONT
  • Epidermal Necrolysis, Toxic
    • Warnings section, Adverse reactions section, Precautions section
    • source: PHONT
  • Epilepsy
    • Warnings section, Adverse reactions section, Precautions section, Mechanism of action section
    • source: PHONT
  • Hypersensitivity
    • Contraindications section, Warnings section, Adverse reactions section, Precautions section
    • source: PHONT
  • Leukemia
    • Warnings section, Adverse reactions section
    • source: PHONT
  • Seizures
    • Indications & usage section, Warnings section, Adverse reactions section, Precautions section
    • source: PHONT
  • Stevens-Johnson Syndrome
    • Adverse reactions section
    • source: PHONT
  • CYP2C19
    • metabolism/PK, Drug interactions section, Pharmacokinetics section
    • source: U.S. Food and Drug Administration
  • CYP2C9
    • metabolism/PK, Drug interactions section, Pharmacokinetics section
    • source: U.S. Food and Drug Administration
  • HLA-B
    • toxicity, Warnings section
    • source: U.S. Food and Drug Administration

last updated 06/08/2015

2. HCSC Label for phenytoin and HLA-B

Genetic testing recommended

Summary

The product monograph for phenytoin (DILANTIN) notes that individuals with the HLA-B*1502 allele have an increased risk of developing Stevens-Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN) when receiving the drug. It further notes that this allele is common in individuals of Asian ancestry, and HLA-B genotyping should be considered as a screening tool in these patients.

Annotation

Phenytoin (DILANTIN) is an anti-epileptic. Excerpts from the phenytoin (DILANTIN) product monograph:

In studies that included small samples of patients of Asian ancestry a strong association was found between the risk of developing SJS/TEN and the presence of HLA-B*1502, an inherited allelic variant of the HLA-B gene. The HLA-B*1502 allele is found almost exclusively in individuals with ancestry across broad areas of Asia. Results of these studies suggest that the presence of the HLA-B*1502 allele may be one of the risk factors for phenytoin-associated SJS/TEN in patients with Asian ancestry.

...physicians should consider HLA-B*1502 genotyping as a screening tool in these patients. Until further information is available, the use of phenytoin and other anti-epileptic drugs associated with SJS/TEN should also be avoided in patients who test positive for the HLA-B*1502 allele.

HLA-B*1502 genotyping as a screening tool has important limitations and must never substitute for appropriate clinical vigilance and patient management.

For the complete product monograph text with sections containing pharmacogenetic information highlighted, see the phenytoin product monograph.

*Disclaimer: The contents of this page have not been endorsed by HCSC and are the sole responsibility of PharmGKB.


Clinical Variants that meet the highest level of criteria, manually curated by PharmGKB, are shown below.

To see more Clinical Variants with lower levels of criteria, click the button at the bottom of the page.

Disclaimer: The PharmGKB's clinical annotations reflect expert consensus based on clinical evidence and peer-reviewed literature available at the time they are written and are intended only to assist clinicians in decision-making and to identify questions for further research. New evidence may have emerged since the time an annotation was submitted to the PharmGKB. The annotations are limited in scope and are not applicable to interventions or diseases that are not specifically identified.

The annotations do not account for individual variations among patients, and cannot be considered inclusive of all proper methods of care or exclusive of other treatments. It remains the responsibility of the health-care provider to determine the best course of treatment for a patient. Adherence to any guideline is voluntary, with the ultimate determination regarding its application to be made solely by the clinician and the patient. PharmGKB assumes no responsibility for any injury or damage to persons or property arising out of or related to any use of the PharmGKB clinical annotations, or for any errors or omissions.

? = Mouse-over for quick help

The table below contains information about pharmacogenomic variants on PharmGKB. Please follow the link in the "Variant" column for more information about a particular variant. Each link in the "Variant" column leads to the corresponding PharmGKB Variant Page. The Variant Page contains summary data, including PharmGKB manually curated information about variant-drug pairs based on individual PubMed publications. The PMIDs for these PubMed publications can be found on the Variant Page.

The tags in the first column of the table indicate what type of information can be found on the corresponding Variant Page.

Links in the "Gene" column lead to PharmGKB Gene Pages.

List of all variant annotations for phenytoin

Gene ? Variant?
(147)
Alternate Names ? Chemicals ? Alleles ?
(+ chr strand)
Function ? Amino Acid?
Translation
No VIP available No VIP available VA CYP2C19 *2 N/A N/A N/A
VIP No VIP available No VIP available CYP2C19 *2A N/A N/A N/A
VIP No VIP available No VIP available CYP2C19 *3A N/A N/A N/A
No VIP available CA VA CYP2C9 *1 N/A N/A N/A
VIP CA VA CYP2C9 *2 N/A N/A N/A
VIP CA VA CYP2C9 *3 N/A N/A N/A
No VIP available No VIP available VA CYP2C9 *17 N/A N/A N/A
No VIP available No VIP available VA CYP2D6 *1 N/A N/A N/A
No VIP available No VIP available VA CYP2D6 *41 N/A N/A N/A
No VIP available No VIP available VA HLA-A *03:01:01:01 N/A N/A N/A
No VIP available No VIP available VA HLA-B *07:02:01 N/A N/A N/A
No VIP available CA VA HLA-B *13:01:01 N/A N/A N/A
No VIP available No VIP available VA HLA-B *15:01:01:01 N/A N/A N/A
VIP CA VA HLA-B *15:02:01 N/A N/A N/A
No VIP available CA VA HLA-B *15:13:01 N/A N/A N/A
No VIP available No VIP available VA HLA-B *37:01:01 N/A N/A N/A
No VIP available No VIP available VA HLA-B *38:02:01 N/A N/A N/A
No VIP available No VIP available VA HLA-B *46:01:01 N/A N/A N/A
No VIP available No VIP available VA HLA-B *51:01:01 N/A N/A N/A
No VIP available No VIP available VA HLA-B *51:02:01 N/A N/A N/A
No VIP available No VIP available VA HLA-B *54:01:01 N/A N/A N/A
No VIP available CA VA HLA-B *56:02 N/A N/A N/A
No VIP available No VIP available VA HLA-C *08:01 N/A N/A N/A
No VIP available No VIP available VA HLA-C *08:01:01 N/A N/A N/A
No VIP available No VIP available VA HLA-C *14:02:01 N/A N/A N/A
No VIP available No VIP available VA HLA-DRB1 *16:02:01 N/A N/A N/A
No VIP available No Clinical Annotations available VA
rs10068980 NC_000005.10:g.161860841G>A, NC_000005.9:g.161287847G>A, NG_011548.1:g.18651G>A, NM_000806.5:c.188-4880G>A, NM_001127643.1:c.188-4880G>A, NM_001127644.1:c.188-4880G>A, NM_001127645.1:c.188-4880G>A, NM_001127648.1:c.188-4880G>A, rs61304955
G > A
SNP
No VIP available CA VA
rs1045642 NC_000007.13:g.87138645A>G, NC_000007.14:g.87509329A>G, NG_011513.1:g.208920T>C, NM_000927.4:c.3435T>C, NP_000918.2:p.Ile1145=, rs10239679, rs11568726, rs117328163, rs17210003, rs2229108, rs386513066, rs60023214, rs9690664
A > G
SNP
I1145I
No VIP available CA VA
rs1051740 NC_000001.10:g.226019633T>C, NC_000001.11:g.225831932T>C, NG_009776.1:g.26837T>C, NM_000120.3:c.337T>C, NM_001136018.3:c.337T>C, NM_001291163.1:c.337T>C, NP_000111.1:p.Tyr113His, NP_001129490.1:p.Tyr113His, NP_001278092.1:p.Tyr113His, XM_005273085.1:c.337T>C, XP_005273142.1:p.Tyr113His, rs16845366, rs17417482, rs1800444, rs2259405, rs3192120, rs52794507, rs59266540
T > C
SNP
Y113H
rs1057910 NC_000010.10:g.96741053A=, NC_000010.10:g.96741053A>C, NC_000010.11:g.94981296A=, NC_000010.11:g.94981296A>C, NG_008385.1:g.47639A=, NG_008385.1:g.47639A>C, NM_000771.3:c.1075A=, NM_000771.3:c.1075A>C, NP_000762.2:p.Ile359=, NP_000762.2:p.Ile359Leu, XM_005269575.1:c.1075A=, XM_005269575.1:c.1075A>C, XP_005269632.1:p.Ile359=, XP_005269632.1:p.Ile359Leu, rs17847042, rs3198471, rs61212474
A > C
SNP
I359L
No VIP available No Clinical Annotations available VA
rs1112122 NC_000023.10:g.151606004G>T, NC_000023.11:g.152437532G>T, NG_007102.1:g.18827C>A, NM_000808.3:c.-27+13614C>A, XM_005274659.1:c.-27+13614C>A, XM_005274660.1:c.-27+13614C>A, XM_006724811.1:c.-27+13614C>A, XM_011531133.1:c.-27+13614C>A, XM_011531134.1:c.-27+13614C>A, rs60180048
G > T
SNP
No VIP available CA VA
rs1128503 NC_000007.13:g.87179601A>G, NC_000007.14:g.87550285A>G, NG_011513.1:g.167964T>C, NM_000927.4:c.1236T>C, NP_000918.2:p.Gly412=, rs116989428, rs17276907, rs2032587, rs2229105, rs28365046, rs386518005, rs58257317
A > G
SNP
G412G
No VIP available No Clinical Annotations available VA
rs1157122 NC_000005.10:g.161892308T>C, NC_000005.9:g.161319314T>C, NG_011548.1:g.50118T>C, NM_000806.5:c.856+1258T>C, NM_001127643.1:c.856+1258T>C, NM_001127644.1:c.856+1258T>C, NM_001127645.1:c.856+1258T>C, NM_001127648.1:c.856+1258T>C, rs57694082
T > C
SNP
No VIP available CA VA
rs12782374 NC_000010.10:g.96695351G>A, NC_000010.11:g.94935594G>A, NG_008385.1:g.1937G>A
G > A
SNP
No VIP available CA VA
rs17183814 NC_000002.11:g.166152389G>A, NC_000002.12:g.165295879G>A, NG_008143.1:g.61478G>A, NM_001040142.1:c.56G>A, NM_001040143.1:c.56G>A, NM_021007.2:c.56G>A, NP_001035232.1:p.Arg19Lys, NP_001035233.1:p.Arg19Lys, NP_066287.2:p.Arg19Lys, XM_005246750.1:c.56G>A, XM_005246750.2:c.56G>A, XM_005246751.1:c.56G>A, XM_005246752.1:c.56G>A, XM_005246753.1:c.56G>A, XM_005246753.2:c.56G>A, XM_005246754.1:c.27-1G>A, XM_005246754.3:c.27-1G>A, XM_011511608.1:c.56G>A, XM_011511609.1:c.56G>A, XP_005246807.1:p.Arg19Lys, XP_005246808.1:p.Arg19Lys, XP_005246809.1:p.Arg19Lys, XP_005246810.1:p.Arg19Lys, XP_011509910.1:p.Arg19Lys, XP_011509911.1:p.Arg19Lys, rs52803852
G > A
SNP
R19K
rs1799853 NC_000010.10:g.96702047C=, NC_000010.10:g.96702047C>T, NC_000010.11:g.94942290C=, NC_000010.11:g.94942290C>T, NG_008385.1:g.8633C=, NG_008385.1:g.8633C>T, NM_000771.3:c.430C=, NM_000771.3:c.430C>T, NP_000762.2:p.Arg144=, NP_000762.2:p.Arg144Cys, XM_005269575.1:c.430C=, XM_005269575.1:c.430C>T, XP_005269632.1:p.Arg144=, XP_005269632.1:p.Arg144Cys, rs17110268, rs28371674, rs33968134, rs60690363
C > T
SNP
R144C
No VIP available CA VA
rs1934969 NC_000010.10:g.96748495A>T, NC_000010.11:g.94988738A>T, NG_008385.1:g.55081A>T, NM_000771.3:c.1292-109A>T, XM_005269575.1:c.1275-728A>T, rs17522303, rs59299689
A > T
SNP
No VIP available CA VA
rs2032582 NC_000007.13:g.87160618A>C, NC_000007.13:g.87160618A>T, NC_000007.14:g.87531302A>C, NC_000007.14:g.87531302A>T, NG_011513.1:g.186947T>A, NG_011513.1:g.186947T>G, NM_000927.4:c.2677T>A, NM_000927.4:c.2677T>G, NP_000918.2:p.Ser893Ala, NP_000918.2:p.Ser893Thr, rs10228331, rs2229106, rs386553610, rs57135550, rs9641018
A > C
SNP
S893A
No VIP available No Clinical Annotations available VA
rs211037 NC_000005.10:g.162101274C>T, NC_000005.9:g.161528280C>T, NG_009290.1:g.38633C>T, NM_000816.3:c.588C>T, NM_198903.2:c.588C>T, NM_198904.2:c.588C>T, NP_000807.2:p.Asn196=, NP_944493.2:p.Asn196=, NP_944494.1:p.Asn196=, XM_005265870.1:c.588C>T, XP_005265927.1:p.Asn196=, rs3765200, rs61071827
C > T
SNP
N196N
No VIP available No Clinical Annotations available VA
rs2229107 NC_000007.13:g.87138659A>T, NC_000007.14:g.87509343A>T, NG_011513.1:g.208906T>A, NM_000927.4:c.3421T>A, NP_000918.2:p.Ser1141Thr, rs17149694, rs56650970, rs59426833
A > T
SNP
S1141T
No VIP available No Clinical Annotations available VA
rs2229944 NC_000005.10:g.161294312G>A, NC_000005.9:g.160721319G>A, NM_000813.2:c.1194C>T, NM_021911.2:c.1308C>T, NP_000804.1:p.Ala398=, NP_068711.1:p.Ala436=, XM_005265867.1:c.1308C>T, XM_005265868.1:c.1194C>T, XM_005265869.1:c.1200C>T, XM_011534501.1:c.558C>T, XP_005265924.1:p.Ala436=, XP_005265925.1:p.Ala398=, XP_005265926.1:p.Ala400=, XP_011532803.1:p.Ala186=, rs118051818, rs386561760
G > A
SNP
A398A
No VIP available CA VA
rs2234922 NC_000001.10:g.226026406A>G, NC_000001.11:g.225838705A>G, NG_009776.1:g.33610A>G, NM_000120.3:c.416A>G, NM_001136018.3:c.416A>G, NM_001291163.1:c.416A>G, NP_000111.1:p.His139Arg, NP_001129490.1:p.His139Arg, NP_001278092.1:p.His139Arg, XM_005273085.1:c.416A>G, XP_005273142.1:p.His139Arg, rs59975602
A > G
SNP
H139R
No VIP available CA VA
rs2279020 NC_000005.10:g.161895883G>A, NC_000005.9:g.161322889G>A, NG_011548.1:g.53693G>A, NM_000806.5:c.1059+15G>A, NM_001127643.1:c.1059+15G>A, NM_001127644.1:c.1059+15G>A, NM_001127645.1:c.1059+15G>A, NM_001127648.1:c.1059+15G>A
G > A
SNP
No VIP available No Clinical Annotations available VA
rs2298771 AB093548.1:c.3199A=, AB093548.1:c.3199A>G, BAC21101.1:p.Thr1067=, BAC21101.1:p.Thr1067Ala, NC_000002.11:g.166892788C>T, NC_000002.12:g.166036278C>T, NG_011906.1:g.42362G>A, NM_001165963.1:c.3199G>A, NM_001165964.1:c.3115G>A, NM_001202435.1:c.3199G>A, NM_006920.4:c.3166G>A, NP_001159435.1:p.Ala1067Thr, NP_001159436.1:p.Ala1039Thr, NP_001189364.1:p.Ala1067Thr, NP_008851.3:p.Ala1056Thr, NR_110598.1:n.618C>T, XM_011511598.1:c.3199G>A, XM_011511599.1:c.3199G>A, XM_011511600.1:c.3199G>A, XM_011511601.1:c.3199G>A, XM_011511602.1:c.3199G>A, XM_011511603.1:c.3196G>A, XM_011511604.1:c.3166G>A, XM_011511605.1:c.3163G>A, XM_011511606.1:c.3115G>A, XM_011511607.1:c.3199G>A, XP_011509900.1:p.Ala1067Thr, XP_011509901.1:p.Ala1067Thr, XP_011509902.1:p.Ala1067Thr, XP_011509903.1:p.Ala1067Thr, XP_011509904.1:p.Ala1067Thr, XP_011509905.1:p.Ala1066Thr, XP_011509906.1:p.Ala1056Thr, XP_011509907.1:p.Ala1055Thr, XP_011509908.1:p.Ala1039Thr, XP_011509909.1:p.Ala1067Thr, XR_922981.1:n.3383G>A, rs17736325, rs52795097, rs57078271
C > -
C > A
SNP
A1067T
No VIP available CA VA
rs2304016 NC_000002.11:g.166168503A>G, NC_000002.12:g.165311993A>G, NG_008143.1:g.77592A>G, NM_001040142.1:c.971-32A>G, NM_001040143.1:c.971-32A>G, NM_021007.2:c.971-32A>G, XM_005246750.1:c.971-32A>G, XM_005246750.2:c.971-32A>G, XM_005246751.1:c.971-32A>G, XM_005246752.1:c.971-32A>G, XM_005246753.1:c.971-32A>G, XM_005246753.2:c.971-32A>G, XM_005246754.1:c.941-32A>G, XM_005246754.3:c.941-32A>G, XM_005246755.1:c.218-32A>G, XM_005246755.3:c.218-32A>G, XM_011511608.1:c.971-32A>G, XM_011511609.1:c.971-32A>G, rs60139689
A > G
SNP
No VIP available CA VA
rs2606345 NC_000015.10:g.74724835C>A, NC_000015.9:g.75017176C>A, NG_008431.1:g.7294C>A, NM_000499.3:c.-27+606G>T, NM_000499.4:c.-27+606G>T, NM_001319216.1:c.-30+606G>T, NM_001319217.1:c.-30+606G>T, XM_005254185.1:c.-30+606G>T, XM_005254186.1:c.-30+330G>T, XM_005254187.1:c.-30+606G>T, XM_005254188.1:c.-30+606G>T, XM_005254189.1:c.-221+606G>T, rs17861098
C > A
SNP
No VIP available No Clinical Annotations available VA
rs28371685 NC_000010.10:g.96740981C>T, NC_000010.11:g.94981224C>T, NG_008385.1:g.47567C>T, NM_000771.3:c.1003C>T, NP_000762.2:p.Arg335Trp, XM_005269575.1:c.1003C>T, XP_005269632.1:p.Arg335Trp, rs60219528
C > T
SNP
R335W
No VIP available No Clinical Annotations available VA
rs28371686 NC_000010.10:g.96741058C>G, NC_000010.11:g.94981301C>G, NG_008385.1:g.47644C>G, NM_000771.3:c.1080C>G, NP_000762.2:p.Asp360Glu, XM_005269575.1:c.1080C>G, XP_005269632.1:p.Asp360Glu, rs57527516
C > G
SNP
D360E
No VIP available No Clinical Annotations available VA
rs28399504 NC_000010.10:g.96522463A>G, NC_000010.11:g.94762706A>G, NG_008384.2:g.5001A>G, NM_000769.1:c.1A>G, NM_000769.2:c.1A>G, NP_000760.1:p.Met1Val
A > G
SNP
M1V
No VIP available No Clinical Annotations available VA
rs2844665 NC_000006.11:g.31006855T=, NC_000006.11:g.31006855T>C, NC_000006.12:g.31039078T=, NC_000006.12:g.31039078T>C, NT_113891.2:g.2518877C=, NT_113891.2:g.2518877C>T, NT_113891.3:g.2518771C=, NT_113891.3:g.2518771C>T, NT_167244.1:g.2318835C=, NT_167244.1:g.2318835C>T, NT_167244.2:g.2368919C=, NT_167244.2:g.2368919C>T, NT_167245.1:g.2301309C=, NT_167245.1:g.2301309C>T, NT_167245.2:g.2295724C=, NT_167245.2:g.2295724C>T, NT_167246.1:g.2355213T=, NT_167246.1:g.2355213T>C, NT_167246.2:g.2349593T=, NT_167246.2:g.2349593T>C, NT_167247.1:g.2388802T=, NT_167247.1:g.2388802T>C, NT_167247.2:g.2383217T=, NT_167247.2:g.2383217T>C, NT_167248.1:g.2300309C=, NT_167248.1:g.2300309C>T, NT_167248.2:g.2294713C=, NT_167248.2:g.2294713C>T, NT_167249.1:g.2339110C=, NT_167249.1:g.2339110C>T, NT_167249.2:g.2339812C=, NT_167249.2:g.2339812C>T, rs115652646, rs117959072, rs13198573, rs16898459, rs60935531, rs6910746
T > C
SNP
No VIP available No Clinical Annotations available VA
rs3094188 NC_000006.11:g.31142245C=, NC_000006.11:g.31142245C>A, NC_000006.12:g.31174468C=, NC_000006.12:g.31174468C>A, NR_026816.1:n.262-198G>T, NR_026816.1:n.262-198T>G, NT_113891.2:g.2657015A=, NT_113891.2:g.2657015A>C, NT_113891.3:g.2656909A=, NT_113891.3:g.2656909A>C, NT_167245.1:g.2439386A=, NT_167245.1:g.2439386A>C, NT_167245.2:g.2433801A=, NT_167245.2:g.2433801A>C, NT_167246.1:g.2490608A=, NT_167246.1:g.2490608A>C, NT_167246.2:g.2484988A=, NT_167246.2:g.2484988A>C, NT_167247.1:g.2524186A=, NT_167247.1:g.2524186A>C, NT_167247.2:g.2518601A=, NT_167247.2:g.2518601A>C, NT_167248.1:g.2438114A=, NT_167248.1:g.2438114A>C, NT_167248.2:g.2432518A=, NT_167248.2:g.2432518A>C, NT_167249.1:g.2477197A=, NT_167249.1:g.2477197A>C, NT_167249.2:g.2477899A=, NT_167249.2:g.2477899A>C, rs113885435, rs116528482, rs117514558, rs59717132
C > A
SNP
No VIP available No Clinical Annotations available VA
rs3130501 NC_000006.11:g.31136453A=, NC_000006.11:g.31136453A>G, NC_000006.12:g.31168676A=, NC_000006.12:g.31168676A>G, NM_001173531.2:c.-2248C>T, NM_001173531.2:c.-2248T>C, NM_001285986.1:c.-3037C>T, NM_001285986.1:c.-3037T>C, NM_001285987.1:c.-2509C>T, NM_001285987.1:c.-2509T>C, NM_002701.5:c.405+1540C>T, NM_002701.5:c.405+1540T>C, NM_203289.5:c.-2734C>T, NM_203289.5:c.-2734T>C, NT_113891.2:g.2651220G=, NT_113891.2:g.2651220G>A, NT_113891.3:g.2651114G=, NT_113891.3:g.2651114G>A, NT_167245.1:g.2433591G=, NT_167245.1:g.2433591G>A, NT_167245.2:g.2428006G=, NT_167245.2:g.2428006G>A, NT_167246.1:g.2484812G=, NT_167246.1:g.2484812G>A, NT_167246.2:g.2479192G=, NT_167246.2:g.2479192G>A, NT_167247.1:g.2518391G=, NT_167247.1:g.2518391G>A, NT_167247.2:g.2512806G=, NT_167247.2:g.2512806G>A, NT_167248.1:g.2432322G=, NT_167248.1:g.2432322G>A, NT_167248.2:g.2426726G=, NT_167248.2:g.2426726G>A, NT_167249.1:g.2471406G=, NT_167249.1:g.2471406G>A, NT_167249.2:g.2472108G=, NT_167249.2:g.2472108G>A, rs115164593, rs117532372, rs57279569
A > G
SNP
No VIP available No Clinical Annotations available VA
rs3130931 NC_000006.11:g.31134888T=, NC_000006.11:g.31134888T>C, NC_000006.12:g.31167111T=, NC_000006.12:g.31167111T>C, NM_001173531.2:c.-683A=, NM_001173531.2:c.-683A>G, NM_001285986.1:c.-1472A=, NM_001285986.1:c.-1472A>G, NM_001285987.1:c.-944A=, NM_001285987.1:c.-944A>G, NM_002701.5:c.406-1064A>G, NM_002701.5:c.406-1064G>A, NM_203289.5:c.-1169A=, NM_203289.5:c.-1169A>G, NT_113891.3:g.2649550C=, NT_113891.3:g.2649550C>T, NT_167245.1:g.2432027T=, NT_167245.1:g.2432027T>C, NT_167245.2:g.2426442T=, NT_167245.2:g.2426442T>C, NT_167246.1:g.2483247C=, NT_167246.1:g.2483247C>T, NT_167246.2:g.2477627C=, NT_167246.2:g.2477627C>T, NT_167247.1:g.2516826C=, NT_167247.1:g.2516826C>T, NT_167247.2:g.2511241C=, NT_167247.2:g.2511241C>T, NT_167248.1:g.2430755C=, NT_167248.1:g.2430755C>T, NT_167248.2:g.2425159C=, NT_167248.2:g.2425159C>T, NT_167249.1:g.2469840C=, NT_167249.1:g.2469840C>T, NT_167249.2:g.2470542C=, NT_167249.2:g.2470542C>T, XM_005272868.1:c.*103C=, XM_005272868.1:c.*103C>T, rs116274342, rs118179370, rs57720136, rs9263801
T > G
T > T
SNP
No VIP available No Clinical Annotations available VA
rs3219151 NC_000005.10:g.161701908C>T, NC_000005.9:g.161128914C>T, NM_000811.2:c.*135C>T, rs17059674, rs57122315
C > T
SNP
No VIP available CA VA
rs3812718 AB093548.1:c.603-91G>A, NC_000002.11:g.166909544C>T, NC_000002.12:g.166053034C>T, NG_011906.1:g.25606G>A, NM_001165963.1:c.603-91G>A, NM_001165964.1:c.603-91G>A, NM_001202435.1:c.603-91G>A, NM_006920.4:c.603-91G>A, XM_011511598.1:c.603-91G>A, XM_011511599.1:c.603-91G>A, XM_011511600.1:c.603-91G>A, XM_011511601.1:c.603-91G>A, XM_011511602.1:c.603-91G>A, XM_011511603.1:c.603-91G>A, XM_011511604.1:c.603-91G>A, XM_011511605.1:c.603-91G>A, XM_011511606.1:c.603-91G>A, XM_011511607.1:c.603-91G>A, XR_922981.1:n.787-91G>A, rs57229005
C > T
SNP
No VIP available No Clinical Annotations available VA
rs3815087 NC_000006.11:g.31093587G=, NC_000006.11:g.31093587G>A, NC_000006.12:g.31125810G=, NC_000006.12:g.31125810G>A, NG_021348.1:g.15980G=, NG_021348.1:g.15980G>A, NM_014068.2:c.-94G=, NM_014068.2:c.-94G>A, NT_113891.2:g.2608294G=, NT_113891.2:g.2608294G>A, NT_113891.3:g.2608188G=, NT_113891.3:g.2608188G>A, NT_167245.1:g.2390757A=, NT_167245.1:g.2390757A>G, NT_167245.2:g.2385172A=, NT_167245.2:g.2385172A>G, NT_167246.1:g.2441942G=, NT_167246.1:g.2441942G>A, NT_167246.2:g.2436322G=, NT_167246.2:g.2436322G>A, NT_167247.1:g.2475510G=, NT_167247.1:g.2475510G>A, NT_167247.2:g.2469925G=, NT_167247.2:g.2469925G>A, NT_167248.1:g.2389410A=, NT_167248.1:g.2389410A>G, NT_167248.2:g.2383814A=, NT_167248.2:g.2383814A>G, XM_011547844.1:c.15-3771A>G, XM_011547844.1:c.15-3771G>A, XM_011547845.1:c.-94G=, XM_011547845.1:c.-94G>A, rs112569884, rs116367638, rs118170884, rs140268645, rs52794797, rs57847399, rs6924947, rs9263698
G > A
SNP
rs4244285 NC_000010.10:g.96541616G>A, NC_000010.11:g.94781859G>A, NG_008384.2:g.24154G>A, NM_000769.1:c.681G>A, NM_000769.2:c.681G>A, NP_000760.1:p.Pro227=, rs116940633, rs17879456, rs60361278
G > A
SNP
P227P
No VIP available No Clinical Annotations available VA
rs4828696 NC_000023.10:g.151581996T>C, NC_000023.11:g.152413524T>C, NG_007102.1:g.42835A>G, NM_000808.3:c.-27+37622A>G, XM_005274659.1:c.-27+37622A>G, XM_005274660.1:c.-27+37622A>G, XM_006724811.1:c.-27+37622A>G, XM_011531133.1:c.-27+37622A>G, XM_011531134.1:c.-27+37622A>G, rs56568387, rs60127194
T > C
SNP
VIP No Clinical Annotations available No Variant Annotations available
rs4986893 NC_000010.10:g.96540410G>A, NC_000010.11:g.94780653G>A, NG_008384.2:g.22948G>A, NM_000769.2:c.636G>A, NP_000760.1:p.Trp212Ter, rs52827375, rs57081121
G > A
SNP
W212*
No VIP available No Clinical Annotations available VA
rs511310 NC_000004.11:g.46240004A>G, NC_000004.12:g.46237987A>G, rs59093609
A > G
SNP
No VIP available No Clinical Annotations available VA
rs6883877 NC_000005.10:g.161851332C>T, NC_000005.9:g.161278338C>T, NG_011548.1:g.9142C>T, NM_000806.5:c.74+448C>T, NM_001127643.1:c.74+448C>T, NM_001127644.1:c.74+448C>T, NM_001127645.1:c.74+448C>T, NM_001127648.1:c.74+448C>T, rs56705003
C > T
SNP
No VIP available No Clinical Annotations available VA
rs6892782 NC_000005.10:g.161842777T>C, NC_000005.9:g.161269783T>C, NG_011548.1:g.587T>C, rs56770940
T > C
SNP
No VIP available CA VA
rs71486745 NC_000010.10:g.96695776_96695777delGT, NC_000010.11:g.94936019_94936020delGT, NG_008385.1:g.2362_2363delGT
GT > -
indel
No VIP available No Clinical Annotations available VA
rs7900194 NC_000010.10:g.96702066G>A, NC_000010.11:g.94942309G>A, NG_008385.1:g.8652G>A, NM_000771.3:c.449G>A, NP_000762.2:p.Arg150His, XM_005269575.1:c.449G>A, XP_005269632.1:p.Arg150His, rs57530584
G > A
SNP
R150H
No VIP available CA VA
rs9332131 NC_000010.10:g.96709039delA, NC_000010.11:g.94949282delA, NG_008385.1:g.15625delA, NM_000771.3:c.817delA, NP_000762.2:p.Lys273Argfs, XM_005269575.1:c.817delA, XP_005269632.1:p.Lys273Argfs
A > -
indel
K273R
No VIP available No Clinical Annotations available VA
rs9469003 NC_000006.11:g.31407828T>C, NC_000006.12:g.31440051T>C, NT_113891.3:g.2920356T>C, NT_167246.2:g.2748090T>C, NT_167249.2:g.2742270T>C, XR_242000.1:n.-1616T>C, XR_246977.1:n.-1616T>C, XR_247382.1:n.-1616T>C, XR_247437.1:n.-1616T>C, XR_926694.1:n.56A>G, XR_952244.1:n.703A>G, XR_953112.1:n.56A>G, rs116070689, rs117062242, rs61671210
T > C
SNP
Alleles, Functions, and Amino Acid Translations are all sourced from dbSNP 147

Overview

Generic Names
  • 5,5-Dwufenylohydantoina
  • 5,5-diphenylhydantoin
  • DPH
  • Difenilhidantoina [Spanish]
  • Dihydantoin
  • Diphenylan Sodium
  • Diphenylhydantoin
  • Diphenylhydantoine [French]
  • Diphenylhydatanoin
  • Fenitoina [INN-Spanish]
  • Phenytoin Sodium
  • Phenytoine
  • Phenytoine [INN-French]
  • Phenytoinum [INN-Latin]
Trade Names
  • Aleviatin
  • Antisacer
  • Auranile
  • Causoin
  • Citrullamon
  • Citrulliamon
  • Comital
  • Comitoina
  • Convul
  • Danten
  • Dantinal
  • Dantoinal
  • Dantoinal klinos
  • Dantoine
  • Denyl
  • Di-Hydan
  • Di-Lan
  • Di-Phetine
  • Didan TDC 250
  • Difenilhidantoina
  • Difenin
  • Difetoin
  • Difhydan
  • Dihycon
  • Dilabid
  • Dilantin
  • Dilantin acid
  • Dilantin-125
  • Dilantine
  • Dillantin
  • Dintoin
  • Dintoina
  • Diphantoin
  • Diphedal
  • Diphedan
  • Diphenat
  • Diphenin
  • Diphenine
  • Diphentoin
  • Diphentyn
  • Diphenylan
  • Ditoinate
  • Ekko
  • Elepsindon
  • Enkelfel
  • Epamin
  • Epanutin
  • Epasmir 5
  • Epdantoin Simple
  • Epdantoine simple
  • Epelin
  • Epifenyl
  • Epihydan
  • Epilan
  • Epilan D
  • Epilan-D
  • Epilantin
  • Epinat
  • Epised
  • Eptal
  • Eptoin
  • Fenantoin
  • Fenidantoin s
  • Fentoin
  • Fenylepsin
  • Fenytoin Dak
  • Fenytoine
  • Gerot-epilan-D
  • Hidan
  • Hidantal
  • Hidantilo
  • Hidantina
  • Hidantina senosian
  • Hidantina vitoria
  • Hidantomin
  • Hindatal
  • Hydantal
  • Hydantin
  • Hydantoin
  • Hydantoinal
  • Hydantol
  • Ictalis simple
  • Idantoil
  • Idantoin
  • Iphenylhydantoin
  • Kessodanten
  • Labopal
  • Lehydan
  • Lepitoin
  • Lepsin
  • Mesantoin
  • Minetoin
  • Neos-Hidantoina
  • Neosidantoina
  • Novantoina
  • Novophenytoin
  • Om hidantoina simple
  • Om-Hydantoine
  • Oxylan
  • Phanantin
  • Phanatine
  • Phenatine
  • Phenatoine
  • Phenhydan
  • Phenhydanin
  • Phenitoin
  • Phentoin
  • Phentytoin
  • Phenytex
  • Phenytoin AWD
  • Phenytoin-Gerot
  • Prompt Phenytoin Sodium
  • Ritmenal
  • Saceril
  • Sanepil
  • Silantin
  • Sinergina
  • Sodanthon
  • Sodantoin
  • Sodanton
  • Solantin
  • Solantoin
  • Solantyl
  • Sylantoic
  • TOIN
  • Tacosal
  • Thilophenyl
  • Toin unicelles
  • Zentronal
  • Zentropil
Brand Mixture Names
  • Dilantin W Phenobarbital 15mg (Phenobarbital + Phenytoin Sodium)
  • Dilantin W Phenobarbital 30mg Cap (Phenobarbital + Phenytoin Sodium)

PharmGKB Accession Id

PA450947

Type(s):

Drug

Description

An anticonvulsant that is used in a wide variety of seizures. It is also an anti-arrhythmic and a muscle relaxant. The mechanism of therapeutic action is not clear, although several cellular actions have been described including effects on ion channels, active transport, and general membrane stabilization. The mechanism of its muscle relaxant effect appears to involve a reduction in the sensitivity of muscle spindles to stretch. Phenytoin has been proposed for several other therapeutic uses, but its use has been limited by its many adverse effects and interactions with other drugs.

Source: Drug Bank

Indication

For the control of generalized tonic-clonic (grand mal) and complex partial (psychomotor, temporal lobe) seizures and prevention and treatment of seizures occurring during or following neurosurgery.

Source: Drug Bank

Other Vocabularies

Information pulled from DrugBank has not been reviewed by PharmGKB.

Pharmacology, Interactions, and Contraindications

Mechanism of Action

Phenytoin acts on sodium channels on the neuronal cell membrane, limiting the spread of seizure activity and reducing seizure propagation. By promoting sodium efflux from neurons, phenytoin tends to stabilize the threshold against hyperexcitability caused by excessive stimulation or environmental changes capable of reducing membrane sodium gradient. This includes the reduction of post-tetanic potentiation at synapses. Loss of post-tetanic potentiation prevents cortical seizure foci from detonating adjacent cortical areas.

Source: Drug Bank

Pharmacology

Phenytoin is an antiepileptic drug which can be useful in the treatment of epilepsy. The primary site of action appears to be the motor cortex where spread of seizure activity is inhibited. Phenytoin reduces the maximal activity of brain stem centers responsible for the tonic phase of tonic-clonic (grand mal) seizures. Phenytoin acts to dampen the unwanted, runaway brain activity seen in seizure by reducing electrical conductance among brain cells. It lacks the sedation effects associated with phenobarbital. There are some indications that phenytoin has other effects, including anxiety control and mood stabilization, although it has never been approved for those purposes by the FDA. Phenytoin is primarily metabolized by CYP2C9.

Source: Drug Bank

Food Interaction

Avoid alcohol.|Take with food to increase bioavailability and reduce irritation.|Do not take calcium, aluminum, magnesium or Iron supplements within 2 hours of taking this medication.

Source: Drug Bank

Absorption, Distribution, Metabolism, Elimination & Toxicity

Biotransformation

Primarily hepatic

Source: Drug Bank

Protein Binding

Highly protein bound, 90%

Source: Drug Bank

Absorption

Bioavailability 70-100% oral, 24.4% for rectal and intravenous administration. Rapid rate of absorption with peak blood concentration expected in 1½ to 3 hours.

Source: Drug Bank

Half-Life

22 hours (range of 7 to 42 hours)

Source: Drug Bank

Toxicity

Oral, mouse: LD 50 = 150 mg/kg; Oral, rat: LD 50 = 1635 mg/kg. Symptoms of overdose include coma, difficulty in pronouncing words correctly, involuntary eye movement, lack of muscle coordination, low blood pressure, nausea, sluggishness, slurred speech, tremors, and vomiting.

Source: Drug Bank

Route of Elimination

Most of the drug is excreted in the bile as inactive metabolites which are then reabsorbed from the intestinal tract and excreted in the urine. Urinary excretion of phenytoin and its metabolites occurs partly with glomerular filtration but, more importantly, by tubular secretion.

Source: Drug Bank

Chemical Properties

Chemical Formula

C15H12N2O2

Source: Drug Bank

Isomeric SMILES

c1ccc(cc1)C2(C(=O)NC(=O)N2)c3ccccc3

Source: OpenEye

Canonical SMILES

O=C1NC(=O)C(N1)(C1=CC=CC=C1)C1=CC=CC=C1

Source: Drug Bank

Average Molecular Weight

252.268

Source: Drug Bank

Monoisotopic Molecular Weight

252.089877638

Source: Drug Bank

SMILES

O=C1NC(=O)C(N1)(C1=CC=CC=C1)C1=CC=CC=C1

Source: Drug Bank

InChI String

InChI=1S/C15H12N2O2/c18-13-15(17-14(19)16-13,11-7-3-1-4-8-11)12-9-5-2-6-10-12/h1-10H,(H2,16,17,18,19)

Source: Drug Bank

PharmGKB Curated Pathways

Pathways created internally by PharmGKB based primarily on literature evidence.

  1. Acetaminophen Pathway (therapeutic doses), Pharmacokinetics
    Stylized diagram showing acetaminophen metabolism and transport in the liver.
  1. Phenytoin Pathway, Pharmacokinetics
    Genes involved in the metabolism of phenytoin in the human liver cell.

External Pathways

Links to non-PharmGKB pathways.

PharmGKB contains no links to external pathways for this drug. To report a pathway, click here.

Genes that are associated with this drug in PharmGKB's database based on (1) variant annotations, (2) literature review, (3) pathways or (4) information automatically retrieved from DrugBank, depending on the "evidence" and "source" listed below.

Curated Information ?

Drug Targets

Gene Description
SCN1A (source: Drug Bank)
SCN5A (source: Drug Bank)

Curated Information ?

EvidenceDrug
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
acetaminophen

Drug Interactions

Interaction Description
alprazolam - phenytoin Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
alprazolam - phenytoin Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
aminophylline - phenytoin Decreased effect of both products (source: Drug Bank)
amiodarone - phenytoin Increases the effect of hydantoin (source: Drug Bank)
amiodarone - phenytoin Increases the effect of hydantoin (source: Drug Bank)
aprepitant - phenytoin The CYP3A4 inducer, phenytoin, may decrease the effect of aprepitant. (source: Drug Bank)
betamethasone - phenytoin The enzyme inducer, phenytoin, may decrease the effect of the corticosteroid, betamethasone. (source: Drug Bank)
capecitabine - phenytoin Capecitabine increases the effect of hydantoin (source: Drug Bank)
capecitabine - phenytoin Capecitabine increases the effect of hydantoin (source: Drug Bank)
chloramphenicol - phenytoin Increases phenytoin, modifies chloramphenicol (source: Drug Bank)
chloramphenicol - phenytoin Increases phenytoin, modifies chloramphenicol (source: Drug Bank)
chlordiazepoxide - phenytoin Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
chlordiazepoxide - phenytoin Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
chlorpheniramine - phenytoin The antihistamine increases the effect of hydantoin (source: Drug Bank)
chlorpheniramine - phenytoin The antihistamine increases the effect of hydantoin (source: Drug Bank)
cimetidine - phenytoin Increases the effect of hydantoin (source: Drug Bank)
cimetidine - phenytoin Increases the effect of hydantoin (source: Drug Bank)
ciprofloxacin - phenytoin Decreases the hydantoin effect (source: Drug Bank)
ciprofloxacin - phenytoin Decreases the hydantoin effect (source: Drug Bank)
clarithromycin - phenytoin Increases the effect and toxicity of phenytoin (source: Drug Bank)
clarithromycin - phenytoin Increases the effect and toxicity of phenytoin (source: Drug Bank)
clomifene - phenytoin The enzyme inducer decreases the effect of hormones (source: Drug Bank)
clomifene - phenytoin The enzyme inducer, phenytoin, decreases the effect of the hormone agent, clomifene. (source: Drug Bank)
clorazepate - phenytoin Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
clozapine - phenytoin Hydantoin decreases the effect of clozapine (source: Drug Bank)
clozapine - phenytoin Hydantoin decreases the effect of clozapine (source: Drug Bank)
cyclosporine - phenytoin The hydantoin decreases the effect of cyclosporine (source: Drug Bank)
cyclosporine - phenytoin The hydantoin decreases the effect of cyclosporine (source: Drug Bank)
delavirdine - phenytoin The anticonvulsant decreases the effect of delavirdine (source: Drug Bank)
delavirdine - phenytoin The anticonvulsant, phenytoin, decreases the effect of delavirdine. (source: Drug Bank)
dexamethasone - phenytoin The enzyme inducer decreases the effect of the corticosteroid (source: Drug Bank)
dexamethasone - phenytoin The enzyme inducer, phenytoin, may decrease the effect of the corticosteroid, dexamethasone. (source: Drug Bank)
diazepam - phenytoin Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
diazepam - phenytoin Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
diethylstilbestrol - phenytoin The enzyme inducer decreases the effect of hormones (source: Drug Bank)
diethylstilbestrol - phenytoin The enzyme inducer, phenytoin, decreases the effect of the hormone agent, diethylstilbestrol. (source: Drug Bank)
disopyramide - phenytoin The hydantoin decreases the effect of disopyramide (source: Drug Bank)
disopyramide - phenytoin The hydantoin decreases the effect of disopyramide (source: Drug Bank)
disulfiram - phenytoin Increases the effect of phenytoin (source: Drug Bank)
disulfiram - phenytoin Increases the effect of phenytoin (source: Drug Bank)
divalproex sodium - phenytoin Valproate increases the effect of hydantoin (source: Drug Bank)
doxycycline - phenytoin The anticonvulsant decreases the effect of doxycycline (source: Drug Bank)
doxycycline - phenytoin The anticonvulsant, phenytoin, decreases the effect of doxycycline. (source: Drug Bank)
estazolam - phenytoin Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
estradiol - phenytoin The enzyme inducer decreases the effect of hormones (source: Drug Bank)
estradiol - phenytoin The enzyme inducer, phenytoin, decreases the effect of the hormone agent, estradiol. (source: Drug Bank)
ethinyl estradiol - phenytoin This product may cause a slight decrease of contraceptive effect (source: Drug Bank)
ethinyl estradiol - phenytoin This product may cause a slight decrease of contraceptive effect (source: Drug Bank)
felbamate - phenytoin Increased phenytoin levels and decreased felbamate levels (source: Drug Bank)
felbamate - phenytoin Increased phenytoin levels and decreased felbamate levels (source: Drug Bank)
felodipine - phenytoin The hydantoin decreases the effect of felodipine (source: Drug Bank)
felodipine - phenytoin The hydantoin decreases the effect of felodipine (source: Drug Bank)
fluconazole - phenytoin Increases the effect of hydantoin (source: Drug Bank)
fluconazole - phenytoin Increases the effect of hydantoin (source: Drug Bank)
fludrocortisone - phenytoin The enzyme inducer, phenytoin, may decrease the effect of the corticosteroid, fludrocortisone. (source: Drug Bank)
fluorouracil - phenytoin Fluorouracil increases the effect of hydantoin (source: Drug Bank)
fluorouracil - phenytoin Fluorouracil increases the effect of hydantoin (source: Drug Bank)
fluoxetine - phenytoin Fluoxetine increases the effect of phenytoin (source: Drug Bank)
fluoxetine - phenytoin Fluoxetine increases the effect of phenytoin (source: Drug Bank)
flurazepam - phenytoin Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
flurazepam - phenytoin Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
folic acid - phenytoin Folic acid decreases the levels of hydantoin (source: Drug Bank)
folic acid - phenytoin Folic acid decreases the levels of hydantoin (source: Drug Bank)
furosemide - phenytoin The hydantoin decreases the effect of furosemide (source: Drug Bank)
furosemide - phenytoin The hydantoin decreases the effect of furosemide (source: Drug Bank)
gabapentin - phenytoin Increases the effect of hydantoin (source: Drug Bank)
gabapentin - phenytoin Increases the effect of hydantoin (source: Drug Bank)
gefitinib - phenytoin This CYP3A4 inducer may reduce gefitinib concentrations and pharmacological effects (source: Drug Bank)
gefitinib - phenytoin The CYP3A4 inducer, phenytoin, may decrease the serum concentration and therapeutic effects of gefitinib. (source: Drug Bank)
hydrocortisone - phenytoin The enzyme inducer decreases the effect of the corticosteroid (source: Drug Bank)
hydrocortisone - phenytoin The enzyme inducer, phenytoin, may decrease the effect of the corticosteroid, hydrocortisone. (source: Drug Bank)
imatinib - phenytoin The hydantoin decreases the levels of imatinib (source: Drug Bank)
imatinib - phenytoin The hydantoin decreases the levels of imatinib (source: Drug Bank)
isoniazid - phenytoin Isoniazid increases the effect of phenytoin in 20% of patients (source: Drug Bank)
isoniazid - phenytoin Isoniazid increases the effect of phenytoin in 20% of patients (source: Drug Bank)
itraconazole - phenytoin Phenytoin decreases the effect of itraconazole (source: Drug Bank)
itraconazole - phenytoin Phenytoin decreases the effect of itraconazole (source: Drug Bank)
lamotrigine - phenytoin Phenytoin may reduce levels of lamotrigine (source: Drug Bank)
lamotrigine - phenytoin Phenytoin may reduce levels of lamotrigine (source: Drug Bank)
levonorgestrel - phenytoin Phenytoin decreases the contraceptive effect (source: Drug Bank)
levonorgestrel - phenytoin Phenytoin decreases the contraceptive effect (source: Drug Bank)
lorazepam - phenytoin Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
mebendazole - phenytoin The hydantoin decreases the efficiency of mebendazole (source: Drug Bank)
medroxyprogesterone - phenytoin The enzyme inducer decreases the effect of hormones (source: Drug Bank)
medroxyprogesterone - phenytoin The enzyme inducer, phenytoin, decreases the effect of the hormone agent, medroxyprogesterone. (source: Drug Bank)
megestrol - phenytoin The enzyme inducer decreases the effect of hormones (source: Drug Bank)
megestrol - phenytoin The enzyme inducer, phenytoin, decreases the effect of the hormone agent, megestrol. (source: Drug Bank)
methadone - phenytoin The hydantoin decreases the effect of methadone (source: Drug Bank)
methadone - phenytoin The hydantoin decreases the effect of methadone (source: Drug Bank)
methotrexate - phenytoin The antineoplasic agent decreases the effect of hydantoin (source: Drug Bank)
methotrexate - phenytoin The antineoplasic agent decreases the effect of hydantoin (source: Drug Bank)
methoxsalen - phenytoin The hydantoin decreases the effect of psoralene (source: Drug Bank)
methoxsalen - phenytoin The hydantoin decreases the effect of psoralene (source: Drug Bank)
mexiletine - phenytoin The hydantoin decreases the effect of mexiletine (source: Drug Bank)
mexiletine - phenytoin The hydantoin decreases the effect of mexiletine (source: Drug Bank)
midazolam - phenytoin Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
midazolam - phenytoin Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
mirtazapine - phenytoin The hydantoins may reduce mirtazapine plasma concentrations and pharmacological effects (source: Drug Bank)
mirtazapine - phenytoin The hydantoins may reduce mirtazapine plasma concentrations and pharmacological effects (source: Drug Bank)
norethindrone - phenytoin This product may cause a slight decrease of contraceptive effect (source: Drug Bank)
norethindrone - phenytoin This product may cause a slight decrease of contraceptive effect (source: Drug Bank)
omeprazole - phenytoin Omeprazole increases the effect of hydantoin (source: Drug Bank)
omeprazole - phenytoin Omeprazole increases the effect of hydantoin (source: Drug Bank)
oxazepam - phenytoin Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
oxcarbazepine - phenytoin Oxcarbazepine increases the effect of hydantoin (source: Drug Bank)
oxcarbazepine - phenytoin Oxcarbazepine increases the effect of hydantoin (source: Drug Bank)
oxtriphylline - phenytoin Decreased effect of both products (source: Drug Bank)
oxyphenbutazone - phenytoin The NSAID increases the hydantoin effect (source: Drug Bank)
oxyphenbutazone - phenytoin The NSAID, oxyphenbutazone, may increase the hydantoin effect of phenytoin. (source: Drug Bank)
phenylbutazone - phenytoin The NSAID increases the hydantoin effect (source: Drug Bank)
phenylbutazone - phenytoin The NSAID, phenylbutazone, may increase the hydantoin effect of phenytoin. (source: Drug Bank)
phenytoin - acenocoumarol Increased hydantoin levels and risk of bleeding (source: Drug Bank)
phenytoin - acenocoumarol Increased hydantoin levels and risk of bleeding (source: Drug Bank)
phenytoin - alprazolam Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
phenytoin - alprazolam Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
phenytoin - aminophylline Decreased effect of both products (source: Drug Bank)
phenytoin - aminophylline Decreased effect of both products (source: Drug Bank)
phenytoin - amiodarone Amiodarone increases the effect of hydantoin (source: Drug Bank)
phenytoin - amiodarone Amiodarone increases the effect of hydantoin (source: Drug Bank)
phenytoin - anisindione Increased hydantoin levels and risk of bleeding (source: Drug Bank)
phenytoin - anisindione Increased hydantoin levels and risk of bleeding (source: Drug Bank)
phenytoin - aprepitant This CYP3A4 inducer decreases the effect of aprepitant (source: Drug Bank)
phenytoin - aprepitant The CYP3A4 inducer, phenytoin, may decrease the effect of aprepitant. (source: Drug Bank)
phenytoin - atracurium Phenytoin decreases the effect of the muscle relaxant (source: Drug Bank)
phenytoin - atracurium Phenytoin decreases the effect of the muscle relaxant (source: Drug Bank)
phenytoin - betamethasone The enzyme inducer decreases the effect of the corticosteroid (source: Drug Bank)
phenytoin - betamethasone The enzyme inducer, phenytoin, may decrease the effect of the corticosteroid, betamethasone. (source: Drug Bank)
phenytoin - bleomycin The antineoplasic agent decreases the effect of hydantoin (source: Drug Bank)
phenytoin - bleomycin The antineoplasic agent decreases the effect of hydantoin (source: Drug Bank)
phenytoin - capecitabine Capecitabine increases the effect of hydantoin (source: Drug Bank)
phenytoin - capecitabine Capecitabine increases the effect of hydantoin (source: Drug Bank)
phenytoin - carboplatin The antineoplasic agent decreases the effect of hydantoin (source: Drug Bank)
phenytoin - carboplatin The antineoplasic agent decreases the effect of hydantoin (source: Drug Bank)
phenytoin - carmustine The antineoplasic agent decreases the effect of hydantoin (source: Drug Bank)
phenytoin - carmustine The antineoplasic agent decreases the effect of hydantoin (source: Drug Bank)
phenytoin - chloramphenicol Increases phenytoin, modifies chloramphenicol (source: Drug Bank)
phenytoin - chloramphenicol Increases phenytoin, modifies chloramphenicol (source: Drug Bank)
phenytoin - chlordiazepoxide Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
phenytoin - chlordiazepoxide Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
phenytoin - chlorotrianisene The enzyme inducer decreases the effect of the hormones (source: Drug Bank)
phenytoin - chlorotrianisene The enzyme inducer, phenytoin, decreases the effect of the hormone agent, chlorotrianisene. (source: Drug Bank)
phenytoin - chlorpheniramine The antihistamine increases the effect of hydantoin (source: Drug Bank)
phenytoin - chlorpheniramine The antihistamine increases the effect of hydantoin (source: Drug Bank)
phenytoin - cimetidine Cimetidine increases the effect of hydantoin (source: Drug Bank)
phenytoin - cimetidine Cimetidine increases the effect of hydantoin (source: Drug Bank)
phenytoin - ciprofloxacin Ciprofloxacin decreases the hydantoin effect (source: Drug Bank)
phenytoin - ciprofloxacin Ciprofloxacin decreases the hydantoin effect (source: Drug Bank)
phenytoin - cisplatin The antineoplasic agent decreases the effect of hydantoin (source: Drug Bank)
phenytoin - cisplatin The antineoplasic agent decreases the effect of hydantoin (source: Drug Bank)
phenytoin - clarithromycin Clarithromycin increases the effect and toxicity of phenytoin (source: Drug Bank)
phenytoin - clarithromycin Clarithromycin increases the effect and toxicity of phenytoin (source: Drug Bank)
phenytoin - clomifene The enzyme inducer decreases the effect of the hormones (source: Drug Bank)
phenytoin - clomifene The enzyme inducer, phenytoin, decreases the effect of the hormone agent, clomifene. (source: Drug Bank)
phenytoin - clorazepate Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
phenytoin - clorazepate Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
phenytoin - clozapine The hydantoin decreases the effect of clozapine (source: Drug Bank)
phenytoin - clozapine The hydantoin decreases the effect of clozapine (source: Drug Bank)
phenytoin - conjugated estrogens The enzyme inducer decreases the effect of the hormones (source: Drug Bank)
phenytoin - conjugated estrogens The enzyme inducer, phenytoin, decreases the effect of the hormone agent, conjugated estrogens. (source: Drug Bank)
phenytoin - cortisone acetate The enzyme inducer decreases the effect of the corticosteroid (source: Drug Bank)
phenytoin - cyclosporine The hydantoin decreases the effect of cyclosporine (source: Drug Bank)
phenytoin - cyclosporine The hydantoin decreases the effect of cyclosporine (source: Drug Bank)
phenytoin - dasatinib Decreased levels/efficacy of dasatinib (source: Drug Bank)
phenytoin - dasatinib Phenytoin may decrease the serum level and efficacy of dasatinib. (source: Drug Bank)
phenytoin - delavirdine The anticonvulsant decreases the effect of delavirdine (source: Drug Bank)
phenytoin - delavirdine The anticonvulsant, phenytoin, decreases the effect of delavirdine. (source: Drug Bank)
phenytoin - dexamethasone The enzyme inducer decreases the effect of the corticosteroid (source: Drug Bank)
phenytoin - dexamethasone The enzyme inducer, phenytoin, may decrease the effect of the corticosteroid, dexamethasone. (source: Drug Bank)
phenytoin - diazepam Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
phenytoin - diazepam Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
phenytoin - diazoxide Diazoxide decreases the hydantoin effect (source: Drug Bank)
phenytoin - diazoxide Diazoxide decreases the efficacy of phenytoin. (source: Drug Bank)
phenytoin - dicumarol Increased hydantoin levels and risk of bleeding (source: Drug Bank)
phenytoin - dicumarol Increased hydantoin levels and risk of bleeding (source: Drug Bank)
phenytoin - diethylstilbestrol The enzyme inducer decreases the effect of the hormones (source: Drug Bank)
phenytoin - diethylstilbestrol The enzyme inducer, phenytoin, decreases the effect of the hormone agent, diethylstilbestrol. (source: Drug Bank)
phenytoin - disopyramide The hydantoin decreases the effect of disopyramide (source: Drug Bank)
phenytoin - disopyramide The hydantoin decreases the effect of disopyramide (source: Drug Bank)
phenytoin - disulfiram Disulfiram increases the effect of phenytoin (source: Drug Bank)
phenytoin - disulfiram Disulfiram increases the effect of phenytoin (source: Drug Bank)
phenytoin - dopamine Risk of severe hypotension (source: Drug Bank)
phenytoin - dopamine Risk of severe hypotension (source: Drug Bank)
phenytoin - doxacurium Phenytoin decreases the effect of the muscle relaxant (source: Drug Bank)
phenytoin - doxacurium Phenytoin decreases the effect of the muscle relaxant (source: Drug Bank)
phenytoin - doxycycline The anticonvulsant decreases the effect of doxycycline (source: Drug Bank)
phenytoin - doxycycline The anticonvulsant, phenytoin, decreases the effect of doxycycline (source: Drug Bank)
phenytoin - dyphylline Decreased effect of both products (source: Drug Bank)
phenytoin - dyphylline Decreased effect of both products (source: Drug Bank)
phenytoin - estazolam Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
phenytoin - estazolam Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
phenytoin - estradiol This product may cause a slight decrease of contraceptive effect (source: Drug Bank)
phenytoin - estriol The enzyme inducer decreases the effect of the hormones (source: Drug Bank)
phenytoin - estriol The enzyme inducer, phenytoin, decreases the effect of the hormone agent, estriol. (source: Drug Bank)
phenytoin - estrone The enzyme inducer decreases the effect of the hormones (source: Drug Bank)
phenytoin - estrone The enzyme inducer, phenytoin, decreases the effect of the hormone agent, estrone. (source: Drug Bank)
phenytoin - ethinyl estradiol This product may cause a slight decrease of contraceptive effect (source: Drug Bank)
phenytoin - felbamate Increased phenytoin levels and decreased felbamate levels (source: Drug Bank)
phenytoin - felbamate Increased phenytoin levels and decreased felbamate levels (source: Drug Bank)
phenytoin - felodipine The hydantoin decreases the effect of felodipine (source: Drug Bank)
phenytoin - felodipine The hydantoin decreases the effect of felodipine (source: Drug Bank)
phenytoin - fluconazole Fluconazole increases the effect of hydantoin (source: Drug Bank)
phenytoin - fluconazole Fluconazole increases the effect of hydantoin (source: Drug Bank)
phenytoin - fludrocortisone The enzyme inducer decreases the effect of the corticosteroid (source: Drug Bank)
phenytoin - fludrocortisone The enzyme inducer, phenytoin, may decrease the effect of the corticosteroid, fludrocortisone. (source: Drug Bank)
phenytoin - fluorouracil Fluorouracil increases the effect of hydantoin (source: Drug Bank)
phenytoin - fluorouracil Fluorouracil increases the effect of hydantoin (source: Drug Bank)
phenytoin - fluoxetine Fluoxetine increases the effect of phenytoin (source: Drug Bank)
phenytoin - fluoxetine Fluoxetine increases the effect of phenytoin (source: Drug Bank)
phenytoin - flurazepam Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
phenytoin - flurazepam Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
phenytoin - fluvoxamine Fluvoxamine increases the effect of hydantoin (source: Drug Bank)
phenytoin - fluvoxamine Fluvoxamine increases the effect of hydantoin (source: Drug Bank)
phenytoin - folic acid folic acid decreases the levels of hydantoin (source: Drug Bank)
phenytoin - furosemide The hydantoin decreases the effect of furosemide (source: Drug Bank)
phenytoin - furosemide The hydantoin decreases the effect of furosemide (source: Drug Bank)
phenytoin - gabapentin Gabapentin increases the effect of hydantoin (source: Drug Bank)
phenytoin - gabapentin Gabapentin increases the effect of hydantoin (source: Drug Bank)
phenytoin - gallamine triethiodide Phenytoin decreases the effect of the muscle relaxant (source: Drug Bank)
phenytoin - gallamine triethiodide Phenytoin decreases the effect of the muscle relaxant (source: Drug Bank)
phenytoin - gefitinib This CYP3A4 inducer may reduce gefitinib plasma concentrations and pharmacological effects (source: Drug Bank)
phenytoin - gefitinib The CYP3A4 inducer, phenytoin, may decrease the serum concentration and therapeutic effects of gefitinib. (source: Drug Bank)
phenytoin - hydrocortisone The enzyme inducer decreases the effect of the corticosteroid (source: Drug Bank)
phenytoin - hydrocortisone The enzyme inducer, phenytoin, may decrease the effect of the corticosteroid, hydrocortisone. (source: Drug Bank)
phenytoin - imatinib The hydantoin decreases the levels of imatinib (source: Drug Bank)
phenytoin - imatinib The hydantoin decreases the levels of imatinib (source: Drug Bank)
phenytoin - irinotecan The hydantoin decreases the effect of irinotecan (source: Drug Bank)
phenytoin - irinotecan The hydantoin decreases the effect of irinotecan (source: Drug Bank)
phenytoin - isoniazid Isoniazid increases the effect of phenytoin in 20% of patients (source: Drug Bank)
phenytoin - isoniazid Isoniazid increases the effect of phenytoin in 20% of patients (source: Drug Bank)
phenytoin - itraconazole Phenytoin decreases the effect of itraconazole (source: Drug Bank)
phenytoin - itraconazole Phenytoin decreases the effect of itraconazole (source: Drug Bank)
phenytoin - lamotrigine Phenytoin may reduce levels of lamotrigine (source: Drug Bank)
phenytoin - lamotrigine Phenytoin may reduce levels of lamotrigine (source: Drug Bank)
phenytoin - levodopa The hydantoin decreases the effect of levodopa (source: Drug Bank)
phenytoin - levodopa The hydantoin decreases the effect of levodopa (source: Drug Bank)
phenytoin - levonorgestrel Phenytoin decreases the contraceptive effect (source: Drug Bank)
phenytoin - levonorgestrel Phenytoin decreases the contraceptive effect (source: Drug Bank)
phenytoin - lopinavir Levels of both drugs are affected (source: Drug Bank)
phenytoin - lopinavir Levels of both drugs are affected (source: Drug Bank)
phenytoin - lorazepam Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
phenytoin - lorazepam Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
phenytoin - mebendazole The hydantoin decreases the efficiency of mebendazole (source: Drug Bank)
phenytoin - mebendazole The hydantoin decreases the efficiency of mebendazole (source: Drug Bank)
phenytoin - medroxyprogesterone The enzyme inducer decreases the effect of the hormones (source: Drug Bank)
phenytoin - medroxyprogesterone The enzyme inducer, phenytoin, decreases the effect of the hormone, medroxyprogesterone. (source: Drug Bank)
phenytoin - megestrol The enzyme inducer decreases the effect of the hormones (source: Drug Bank)
phenytoin - megestrol The enzyme inducer, phenytoin, decreases the effect of the hormone, megestrol. (source: Drug Bank)
phenytoin - mestranol This product may cause a slight decrease of contraceptive effect (source: Drug Bank)
phenytoin - mestranol This product may cause a slight decrease of contraceptive effect (source: Drug Bank)
phenytoin - methotrexate The antineoplasic agent decreases the effect of hydantoin (source: Drug Bank)
phenytoin - methotrexate The antineoplasic agent decreases the effect of hydantoin (source: Drug Bank)
phenytoin - methoxsalen The hydantoin decreases the effect of psoralene (source: Drug Bank)
phenytoin - methoxsalen The hydantoin decreases the effect of psoralene (source: Drug Bank)
phenytoin - methylprednisolone The enzyme inducer decreases the effect of the corticosteroid (source: Drug Bank)
phenytoin - methylprednisolone The enzyme inducer, phenytoin, may decrease the effect of the corticosteroid, methylprednisolone. (source: Drug Bank)
phenytoin - metocurine Phenytoin decreases the effect of the muscle relaxant (source: Drug Bank)
phenytoin - metocurine Phenytoin decreases the effect of the muscle relaxant (source: Drug Bank)
phenytoin - metyrapone The combination renders the test invalid (source: Drug Bank)
phenytoin - metyrapone The combination renders the test invalid (source: Drug Bank)
phenytoin - mexiletine The hydantoin decreases the effect of mexiletine (source: Drug Bank)
phenytoin - mexiletine The hydantoin decreases the effect of mexiletine (source: Drug Bank)
phenytoin - midazolam Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
phenytoin - midazolam Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
phenytoin - mirtazapine The hydantoins may reduce mirtazapine plasma concentrations and pharmacological effects (source: Drug Bank)
phenytoin - mirtazapine The hydantoins may reduce mirtazapine plasma concentrations and pharmacological effects (source: Drug Bank)
phenytoin - mivacurium Phenytoin decreases the effect of the muscle relaxant (source: Drug Bank)
phenytoin - mivacurium Phenytoin decreases the effect of the muscle relaxant (source: Drug Bank)
phenytoin - nisoldipine Phenytoin decreases the efficiency of nisoldipine (source: Drug Bank)
phenytoin - nisoldipine Phenytoin decreases the efficiency of nisoldipine (source: Drug Bank)
phenytoin - norethindrone This product may cause a slight decrease of contraceptive effect (source: Drug Bank)
phenytoin - norethindrone This product may cause a slight decrease of contraceptive effect (source: Drug Bank)
phenytoin - omeprazole Omeprazole increases the effect of hydantoin (source: Drug Bank)
phenytoin - omeprazole Omeprazole increases the effect of hydantoin (source: Drug Bank)
phenytoin - oxazepam Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
phenytoin - oxazepam Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
phenytoin - oxcarbazepine Oxcarbazepine increases the effect of hydantoin (source: Drug Bank)
phenytoin - oxcarbazepine Oxcarbazepine increases the effect of hydantoin (source: Drug Bank)
phenytoin - oxtriphylline Decreased effect of both products (source: Drug Bank)
phenytoin - oxtriphylline Decreased effect of both products (source: Drug Bank)
phenytoin - oxyphenbutazone The NSAID increases the effect of hydantoin (source: Drug Bank)
phenytoin - oxyphenbutazone The NSAID, oxphenbutazone, may increase the effect of hydantoin of phenytoin. (source: Drug Bank)
phenytoin - pancuronium Phenytoin decreases the effect of the muscle relaxant (source: Drug Bank)
phenytoin - pancuronium Phenytoin decreases the effect of the muscle relaxant (source: Drug Bank)
phenytoin - paramethasone The enzyme inducer decreases the effect of the corticosteroid (source: Drug Bank)
phenytoin - paramethasone The enzyme inducer, phenytoin, may decrease the effect of the corticosteroid, paramethasone. (source: Drug Bank)
phenytoin - phenylbutazone The NSAID increases the effect of hydantoin (source: Drug Bank)
phenytoin - phenylbutazone The NSAID, phenylbutazone, may increase the effect of hydantoin of phenytoin. (source: Drug Bank)
phenytoin - posaconazole Modifications of drug levels for both agents (source: Drug Bank)
phenytoin - posaconazole Modifications of drug levels for both agents (source: Drug Bank)
phenytoin - praziquantel Markedly lower praziquantel levels (source: Drug Bank)
phenytoin - praziquantel Markedly lower praziquantel levels (source: Drug Bank)
phenytoin - prednisolone The enzyme inducer decreases the effect of the corticosteroid (source: Drug Bank)
phenytoin - prednisolone The enzyme inducer, phenytoin, may decrease the effect of the corticosteroid, prednisolone. (source: Drug Bank)
phenytoin - prednisone The enzyme inducer decreases the effect of the corticosteroid (source: Drug Bank)
phenytoin - prednisone The enzyme inducer, phenytoin, may decrease the effect of the corticosteroid, prednisone. (source: Drug Bank)
phenytoin - quazepam Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
phenytoin - quazepam Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
phenytoin - quetiapine Phenytoin decreases the effect of quetiapine (source: Drug Bank)
phenytoin - quetiapine Phenytoin decreases the effect of quetiapine (source: Drug Bank)
phenytoin - quinestrol The enzyme inducer decreases the effect of the hormones (source: Drug Bank)
phenytoin - quinestrol The enzyme inducer, phenytoin, decreases the effect of the hormone agent, quinestrol. (source: Drug Bank)
phenytoin - quinidine The anticonvulsant decreases the effect of quinidine (source: Drug Bank)
phenytoin - quinidine The anticonvulsant, phenytoin, decreases the effect of quinidine. (source: Drug Bank)
phenytoin - rifampin Rifampin decreases the effect of hydantoin (source: Drug Bank)
phenytoin - rifampin Rifampin decreases the effect of hydantoin (source: Drug Bank)
phenytoin - sertraline Sertraline increases the effect of hydantoin (source: Drug Bank)
phenytoin - sertraline Sertraline increases the effect of hydantoin (source: Drug Bank)
phenytoin - sirolimus The hydantoin decreases sirolimus levels (source: Drug Bank)
phenytoin - sirolimus The hydantoin decreases sirolimus levels (source: Drug Bank)
phenytoin - sodium Valproate increases the effect of hydantoin (source: Drug Bank)
phenytoin - sodium Valproate increases the effect of hydantoin (source: Drug Bank)
phenytoin - sucralfate Sucralfate decreases the effect of hydantoin (source: Drug Bank)
phenytoin - sucralfate Sucralfate decreases the effect of hydantoin (source: Drug Bank)
phenytoin - sulfadiazine The sulfonamide increases the effect of hydantoin (source: Drug Bank)
phenytoin - sulfadiazine The sulfonamide increases the effect of hydantoin (source: Drug Bank)
phenytoin - sulfamethizole The sulfonamide increases the effect of hydantoin (source: Drug Bank)
phenytoin - sulfamethizole The sulfonamide increases the effect of hydantoin (source: Drug Bank)
phenytoin - sunitinib Possible decrease in sunitinib levels (source: Drug Bank)
phenytoin - sunitinib Possible decrease in sunitinib levels (source: Drug Bank)
phenytoin - tacrolimus The hydantoin decreases the effect of tacrolimus (source: Drug Bank)
phenytoin - tacrolimus The hydantoin decreases the effect of tacrolimus (source: Drug Bank)
phenytoin - telithromycin Telithromycin may possibly increase the agent effect/toxicity (source: Drug Bank)
phenytoin - telithromycin Telithromycin may possibly increase the effect and toxicity of phenytoin. (source: Drug Bank)
phenytoin - temazepam Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
phenytoin - temazepam Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
phenytoin - theophylline Decreased effect of both products (source: Drug Bank)
phenytoin - theophylline Decreased effect of both products (source: Drug Bank)
phenytoin - thiotepa Possible increase in thiotepa levels (source: Drug Bank)
phenytoin - thiotepa Possible increase in thiotepa levels (source: Drug Bank)
phenytoin - ticlopidine Ticlopidine increases the effect of hydantoin (source: Drug Bank)
phenytoin - ticlopidine Ticlopidine increases the effect of hydantoin (source: Drug Bank)
phenytoin - topiramate Increased phenytoin/decreased topiramate (source: Drug Bank)
phenytoin - topiramate Increased phenytoin/decreased topiramate (source: Drug Bank)
phenytoin - triamcinolone The enzyme inducer decreases the effect of the corticosteroid (source: Drug Bank)
phenytoin - triamcinolone The enzyme inducer, phenytoin, may decrease the effect of the corticosteroid, triamcinolone. (source: Drug Bank)
phenytoin - triazolam Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
phenytoin - triazolam Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
phenytoin - trimethoprim Trimethoprim increases the effect of hydantoin (source: Drug Bank)
phenytoin - trimethoprim Trimethoprim increases the effect of hydantoin (source: Drug Bank)
phenytoin - trioxsalen The hydantoin decreases the effect of psoralene (source: Drug Bank)
phenytoin - trioxsalen The hydantoin decreases the effect of psoralene (source: Drug Bank)
phenytoin - tubocurarine Phenytoin decreases the effect of the muscle relaxant (source: Drug Bank)
phenytoin - tubocurarine Phenytoin decreases the effect of the muscle relaxant (source: Drug Bank)
phenytoin - vecuronium Phenytoin decreases the effect of the muscle relaxant (source: Drug Bank)
phenytoin - vecuronium Phenytoin decreases the effect of the muscle relaxant (source: Drug Bank)
phenytoin - vigabatrin Vigabatrin decreases the effect of hydantoin (source: Drug Bank)
phenytoin - vigabatrin Vigabatrin decreases the effect of hydantoin (source: Drug Bank)
phenytoin - vinblastine The antineoplasic agent decreases the effect of hydantoin (source: Drug Bank)
phenytoin - vinblastine The antineoplasic agent decreases the effect of hydantoin (source: Drug Bank)
phenytoin - voriconazole The hydantoin decreases the effect of voriconazole (source: Drug Bank)
phenytoin - voriconazole The hydantoin decreases the effect of voriconazole (source: Drug Bank)
phenytoin - warfarin Increased hydantoin levels and risk of bleeding (source: Drug Bank)
phenytoin - warfarin Increased hydantoin levels and risk of bleeding (source: Drug Bank)
praziquantel - phenytoin Markedly lower praziquantel levels (source: Drug Bank)
prednisolone - phenytoin The enzyme inducer decreases the effect of the corticosteroid (source: Drug Bank)
prednisolone - phenytoin The enzyme inducer, phenytoin, may decrease the effect of the corticosteroid, prednisolone. (source: Drug Bank)
prednisone - phenytoin The enzyme inducer decreases the effect of the corticosteroid (source: Drug Bank)
prednisone - phenytoin The enzyme inducer, phenytoin, may decrease the effect of the corticosteroid, prednisone. (source: Drug Bank)
quetiapine - phenytoin Phenytoin decreases the effect of quetiapine (source: Drug Bank)
quetiapine - phenytoin Phenytoin decreases the effect of quetiapine (source: Drug Bank)
quinidine - phenytoin The anticonvulsant decreases the effect of quinidine (source: Drug Bank)
quinidine - phenytoin The anticonvulsant, phenytoin, decreases the effect of quinidine. (source: Drug Bank)
rifampin - phenytoin Rifampin decreases the effect of the hydantoin (source: Drug Bank)
rifampin - phenytoin Rifampin decreases the effect of the hydantoin (source: Drug Bank)
telithromycin - phenytoin Telithromycin may possibly increase this agent effect/toxicity (source: Drug Bank)
telithromycin - phenytoin Phenytoin may decrease the plasma concentration of Telithromycin by increasing its metabolism. Consider alternate therapy. (source: Drug Bank)
temazepam - phenytoin Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
theophylline - phenytoin Decreased effect of both products (source: Drug Bank)
theophylline - phenytoin Decreased effect of both products (source: Drug Bank)
ticlopidine - phenytoin Ticlopidine increases the effect of hydantoin (source: Drug Bank)
ticlopidine - phenytoin Ticlopidine may decrease the metabolism and clearance of Phenytoin. Consider alternate therapy or monitor for adverse/toxic effects of Phenytoin if Ticlopidine is initiated, discontinued or dose changed. (source: Drug Bank)
tipranavir - phenytoin Phenytoin decreases the concentration of Tipranavir. Monitor for decreased Tipranavir efficacy. (source: Drug Bank)
tolbutamide - phenytoin Tolbutamide, a strong CYP2C9 inhibitor, may decrease the metabolism and clearance of Phenytoin. Consider alternate therapy or monitor for changes in Phenytoin therapeutic and adverse effects if Tolbutamide is initiated, discontinued or dose changed. (source: Drug Bank)
tolbutamide - phenytoin Tolbutamide, a strong CYP2C9 inhibitor, may decrease the metabolism and clearance of Phenytoin. Consider alternate therapy or monitor for changes in Phenytoin therapeutic and adverse effects if Tolbutamide is initiated, discontinued or dose changed. (source: Drug Bank)
tramadol - phenytoin Phenytoin may decrease the effect of Tramadol by increasing Tramadol metabolism and clearance. (source: Drug Bank)
trazodone - phenytoin The CYP3A4 inducer, Phenytoin, may decrease Trazodone efficacy by increasing Trazodone metabolism and clearance. Monitor for changes in Trazodone efficacy/toxicity if Phenytoin is initiated, discontinued or dose changed. (source: Drug Bank)
trazodone - phenytoin The CYP3A4 inducer, Phenytoin, may decrease Trazodone efficacy by increasing Trazodone metabolism and clearance. Monitor for changes in Trazodone efficacy/toxicity if Phenytoin is initiated, discontinued or dose changed. (source: Drug Bank)
triamcinolone - phenytoin The enzyme inducer decreases the effect of the corticosteroid (source: Drug Bank)
triamcinolone - phenytoin The enzyme inducer, phenytoin, may decrease the effect of the corticosteroid, triamcinolone. (source: Drug Bank)
triazolam - phenytoin Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
triazolam - phenytoin Possible increased levels of the hydantoin, decrease of benzodiazepine (source: Drug Bank)
triprolidine - phenytoin The CNS depressants, Triprolidine and Phenytoin, may increase adverse/toxic effects due to additivity. Monitor for increased CNS depressant effects during concomitant therapy. (source: Drug Bank)
triprolidine - phenytoin The CNS depressants, Triprolidine and Phenytoin, may increase adverse/toxic effects due to additivity. Monitor for increased CNS depressant effects during concomitant therapy. (source: Drug Bank)
verapamil - phenytoin Verapamil may increase the serum concentration of Phenytoin by decreasing its metabolism. Monitor for changes in the therapeutic/adverse effects of Phenytoin if Verapamil is initiated, discontinued or dose changed. (source: Drug Bank)
voriconazole - phenytoin Voriconazole may increase the serum concentration of phenytoin by decreasing its metabolism. Phenytoin may increase the serum concentration of voriconazole by increasing its metabolism. Consider alternate antifungal therapy or monitor for voriconazole therapy failure and phenytoin toxicity. (source: Drug Bank)
warfarin - phenytoin Warfarin may increase the serum concentration of phenytoin possibly by competing for CYP2C9 metabolism. Phenytoin may increase the anticoagulant effect of warfarin. Monitor phenytoin levels, prothrombin time, and therapeutic and adverse effects of both agents during concomitant therapy. (source: Drug Bank)

Curated Information ?

Relationships from National Drug File - Reference Terminology (NDF-RT)

May Treat
May Prevent
Contraindicated With

Publications related to phenytoin: 131

No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
Association of HLA-B*15:13 and HLA-B*15:02 with phenytoin-induced severe cutaneous adverse reactions in a Malay population. The pharmacogenomics journal. 2016. Chang C-C, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
Associations between HLA class I and cytochrome P450 2C9 genetic polymorphisms and phenytoin-related severe cutaneous adverse reactions in a Thai population. Pharmacogenetics and genomics. 2016. Tassaneeyakul Wichittra, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Stevens-Johnson syndrome and toxic epidermal necrolysis: an update on pharmacogenetics studies in drug-induced severe skin reaction. Pharmacogenomics. 2015. Rufini Sara, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Development of a pharmacogenetic-based warfarin dosing algorithm and its performance in Brazilian patients: highlighting the importance of population-specific calibration. Pharmacogenomics. 2015. Santos Paulo Caleb Junior Lima, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
CYP2C9, CYP2C19, ABCB1 genetic polymorphisms and phenytoin plasma concentrations in Mexican-Mestizo patients with epilepsy. The pharmacogenomics journal. 2015. Ortega-Vázquez A, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Individualized phenytoin therapy for Japanese pediatric patients with epilepsy based on CYP2C9 and CYP2C19 genotypes. Therapeutic drug monitoring. 2015. Yamamoto Yoshiaki, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Role of dermatology in pharmacogenomics: drug-induced skin injury. Pharmacogenomics. 2015. Borroni Riccardo G. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available VIP No VIP available
PharmGKB summary: very important pharmacogene information for human leukocyte antigen B. Pharmacogenetics and genomics. 2015. Barbarino Julia M, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
Association between HLA-B*15:02 allele and antiepileptic drug-induced severe cutaneous reactions in Hong Kong Chinese: a population-based study. Hong Kong medical journal = Xianggang yi xue za zhi / Hong Kong Academy of Medicine. 2014. Kwan P K L, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
T Cell-Mediated Hypersensitivity Reactions to Drugs. Annual review of medicine. 2014. Pavlos Rebecca, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
HLA-B∗1502 is associated with carbamazepine induced Stevens-Johnson syndrome in North Indian population. Human immunology. 2014. Aggarwal Ritu, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Clinical Pharmacogenetics Implementation Consortium (CPIC) Guidelines for CYP2C9 and HLA-B Genotype and Phenytoin Dosing. Clinical pharmacology and therapeutics. 2014. Caudle Kelly E, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
Genetic variants associated with phenytoin-related severe cutaneous adverse reactions. JAMA : the journal of the American Medical Association. 2014. Chung Wen-Hung, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available VA No VIP available No VIP available
Profound reduction in the tamoxifen active metabolite endoxifen in a patient on phenytoin for epilepsy compared with a CYP2D6 genotype matched cohort. Pharmacogenetics and genomics. 2014. Gryn Steven E, et al. PubMed
No Dosing Guideline available No Drug Label available CA No Variant Annotation available No VIP available No VIP available
Association of SCN1A, SCN2A and ABCC2 gene polymorphisms with the response to antiepileptic drugs in Chinese Han patients with epilepsy. Pharmacogenomics. 2014. Ma Chun-Lai, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
Pharmacogenetics of antiepileptic drug-induced hypersensitivity. Pharmacogenomics. 2014. Bloch Katarzyna M, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Expansion of a PBPK model to predict disposition in pregnant women of drugs cleared via multiple CYP enzymes, including CYP2B6, CYP2C9 and CYP2C19. British journal of clinical pharmacology. 2014. Ke Alice Ban, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Understanding variability with voriconazole using a population pharmacokinetic approach: implications for optimal dosing. The Journal of antimicrobial chemotherapy. 2014. Dolton Michael J, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Impact of CYP polymorphisms, ethnicity and sex differences in metabolism on dosing strategies: the case of efavirenz. European journal of clinical pharmacology. 2014. Naidoo Panjasaram, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available VA No VIP available No VIP available
HLA-A*02:01:01/-B*35:01:01/-C*04:01:01 haplotype associated with lamotrigine-induced maculopapular exanthema in Mexican Mestizo patients. Pharmacogenomics. 2014. Fricke-Galindo Ingrid, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available VA No VIP available No VIP available
Gene-wide tagging study of the effects of common genetic polymorphisms in the alpha subunits of the GABAA receptor on epilepsy treatment response. Pharmacogenomics. 2013. Hung Chin-Chuan, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available VA No VIP available No VIP available
Specific HLA types are associated with antiepileptic drug-induced Stevens-Johnson syndrome and toxic epidermal necrolysis in Japanese subjects. Pharmacogenomics. 2013. Kaniwa Nahoko, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available VA No VIP available No VIP available
GABRG2, rs211037 is associated with epilepsy susceptibility, but not with antiepileptic drug resistance and febrile seizures. Pharmacogenetics and genomics. 2013. Balan Shabeesh, et al. PubMed
HLA-B alleles associated with severe cutaneous reactions to antiepileptic drugs in Han Chinese. Epilepsia. 2013. Cheung Ying-Kit, et al. PubMed
No Dosing Guideline available No Drug Label available CA No Variant Annotation available No VIP available No VIP available
SCN1A, SCN2A and SCN3A gene polymorphisms and responsiveness to antiepileptic drugs: a multicenter cohort study and meta-analysis. Pharmacogenomics. 2013. Haerian Batoul Sadat, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Challenges in pharmacogenetics. European journal of clinical pharmacology. 2013. Cascorbi Ingolf, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
Phenobarbital-induced severe cutaneous adverse drug reactions are associated with CYP2C19*2 in Thai children. Pediatric allergy and immunology : official publication of the European Society of Pediatric Allergy and Immunology. 2013. Manuyakorn Wiparat, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
Severe drug-induced hypersensitivity syndrome with a shared HLA-B allele. The Medical journal of Australia. 2012. Harding Damian J, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
PharmGKB summary: phenytoin pathway. Pharmacogenetics and genomics. 2012. Thorn Caroline F, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
Neurological toxicity after phenytoin infusion in a pediatric patient with epilepsy: influence of CYP2C9, CYP2C19 and ABCB1 genetic polymorphisms. The pharmacogenomics journal. 2012. Dorado P, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
Genetic and immune predictors for hypersensitivity syndrome to antiepileptic drugs. Translational research : the journal of laboratory and clinical medicine. 2012. Neuman Manuela G, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available VA No VIP available No VIP available
Genome-wide mapping for clinically relevant predictors of lamotrigine- and phenytoin-induced hypersensitivity reactions. Pharmacogenomics. 2012. McCormack Mark, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Lack of association between ABCC2 gene variants and treatment response in epilepsy. Pharmacogenomics. 2012. Hilger Eva, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Drug hypersensitivity and human leukocyte antigens of the major histocompatibility complex. Annual review of pharmacology and toxicology. 2012. Bharadwaj Mandvi, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
HLA-B*1502 allele is associated with a cross-reactivity pattern of cutaneous adverse reactions to antiepileptic drugs. The Journal of international medical research. 2012. Wang J, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available VIP No VIP available
PharmGKB summary: very important pharmacogene information for cytochrome P450, family 2, subfamily C, polypeptide 19. Pharmacogenetics and genomics. 2011. Scott Stuart A, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Possible role of CYP2C9 & CYP2C19 single nucleotide polymorphisms in drug refractory epilepsy. The Indian journal of medical research. 2011. Lakhan Ram, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available VA No VIP available No VIP available
Genome-Wide Association study of Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis in Europe. Orphanet journal of rare diseases. 2011. Genin Emmanuelle, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
Pharmacogenomic association study on the role of drug metabolizing, drug transporters and drug target gene polymorphisms in drug-resistant epilepsy in a north Indian population. Indian journal of human genetics. 2011. Kumari Ritu, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
CYP2C9 polymorphism in patients with epilepsy: genotypic frequency analyzes andphenytoin adverse reactions correlation. Arquivos de neuro-psiquiatria. 2011. Twardowschy Carlos Alexandre, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Pharmacogenetics of drug-induced birth defects: what is known so far?. Pharmacogenomics. 2011. Wilffert Bob, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Pharmacogenetics: From Bench to Byte- An Update of Guidelines. Clinical pharmacology and therapeutics. 2011. Swen J J, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
SCN1A splice variants exhibit divergent sensitivity to commonly used antiepileptic drugs. Epilepsia. 2011. Thompson Christopher H, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available VIP No VIP available
Very important pharmacogene summary: ABCB1 (MDR1, P-glycoprotein). Pharmacogenetics and genomics. 2011. Hodges Laura M, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Gene-wide tagging study of the association between ABCC2, ABCC5 and ABCG2 genetic polymorphisms and multidrug resistance in epilepsy. Pharmacogenomics. 2011. Kwan Patrick, et al. PubMed
HLA-B*1502 genotyping in two Chinese patients with phenytoin-induced Stevens-Johnson syndrome. Epilepsy & behavior : E&B. 2011. Min Fu-Li, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
A candidate gene study of antiepileptic drug tolerability and efficacy identifies an association of CYP2C9 variants with phenytoin toxicity. European journal of neurology : the official journal of the European Federation of Neurological Societies. 2011. Depondt C, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
Phenytoin-induced Stevens-Johnson syndrome with negative HLA-B*1502 allele in mainland China: Two cases. Seizure : the journal of the British Epilepsy Association. 2011. Hu Fa-Yun, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Genome-wide association study of serious blistering skin rash caused by drugs. The pharmacogenomics journal. 2011. Shen Y, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
Influence of CYP2C9 genetic polymorphism and undernourishment on plasma-free phenytoin concentrations in epileptic patients. Therapeutic drug monitoring. 2010. Ramasamy Kesavan, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
[Development of rapid genotyping methods for single nucleotide polymorphisms of cytochrome P450 2C9 (CYP2C9) and cytochrome P450 2C19 (CYP2C19) and their clinical application in pediatric patients with epilepsy]. Yakugaku zasshi : Journal of the Pharmaceutical Society of Japan. 2011. Yamamoto Yoshiaki, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
Genetic polymorphisms in sex hormone metabolizing genes and drug response in women with epilepsy. Pharmacogenomics. 2010. Grover Sandeep, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Transporter hypothesis of drug-resistant epilepsy: challenges for pharmacogenetic approaches. Pharmacogenomics. 2010. Potschka Heidrun. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
Absence of a general association between ABCB1 genetic variants and response to antiepileptic drugs in epilepsy patients. Biochimie. 2010. Grover Sandeep, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Medications and glucose-6-phosphate dehydrogenase deficiency: an evidence-based review. Drug safety : an international journal of medical toxicology and drug experience. 2010. Youngster Ilan, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available VIP No VIP available
PharmGKB summary: very important pharmacogene information for CYP2B6. Pharmacogenetics and genomics. 2010. Thorn Caroline F, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
Influence of CYP2C9 and CYP2C19 genetic polymorphisms on phenytoin-induced neurological toxicity in Indian epileptic patients. European journal of clinical pharmacology. 2010. Kesavan Ramasamy, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Cutaneous adverse drug reactions seen in a tertiary hospital in Johor, Malaysia. International journal of dermatology. 2010. Ding Wen Yi, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Genetic profile of patients with epilepsy on first-line antiepileptic drugs and potential directions for personalized treatment. Pharmacogenomics. 2010. Grover Sandeep, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Pharmacokinetic and pharmacodynamic interactions between the immunosuppressant sirolimus and the lipid-lowering drug ezetimibe in healthy volunteers. Clinical pharmacology and therapeutics. 2010. Oswald S, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
What is the role of lidocaine or phenytoin in tricyclic antidepressant-induced cardiotoxicity?. Clinical toxicology (Philadelphia, Pa.). 2010. Foianini Anthony, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available VIP No VIP available
Cytochrome P450 2C9-CYP2C9. Pharmacogenetics and genomics. 2010. Van Booven Derek, et al. PubMed
Common risk allele in aromatic antiepileptic-drug induced Stevens-Johnson syndrome and toxic epidermal necrolysis in Han Chinese. Pharmacogenomics. 2010. Hung Shuen-Iu, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
CYP2C9*1B promoter polymorphisms, in linkage with CYP2C19*2, affect phenytoin autoinduction of clearance and maintenance dose. The Journal of pharmacology and experimental therapeutics. 2010. Chaudhry Amarjit S, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Key factors in the discovery and development of new antiepileptic drugs. Nature reviews. Drug discovery. 2010. Bialer Meir, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
Maternal EPHX1 polymorphisms and risk of phenytoin-induced congenital malformations. Pharmacogenetics and genomics. 2010. Azzato Elizabeth M, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
CYP2C9, CYP2C19, and ABCB1 genotype and hospitalization for phenytoin toxicity. Journal of clinical pharmacology. 2009. Hennessy Sean, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Warfarin interactions with substances listed in drug information compendia and in the FDA-approved label for warfarin sodium. Clinical pharmacology and therapeutics. 2009. Anthony M, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
Differential role of sodium channels SCN1A and SCN2A gene polymorphisms with epilepsy and multiple drug resistance in the north Indian population. British journal of clinical pharmacology. 2009. Lakhan Ram, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
CYP2C9 amino acid residues influencing phenytoin turnover and metabolite regio- and stereochemistry. The Journal of pharmacology and experimental therapeutics. 2009. Mosher Carrie M, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Genetic Polymorphism of the Human Cytochrome P450 2C9 Gene and Its Clinical Significance. Current drug metabolism. 2009. Wang B, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Prediction of the effects of genetic polymorphism on the pharmacokinetics of CYP2C9 substrates from in vitro data. Pharmaceutical research. 2009. Kusama Makiko, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Epilepsy pharmacogenetics. Pharmacogenomics. 2009. Kasperavici¿te Dalia, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Gene-wide tagging study of association between ABCB1 polymorphisms and multidrug resistance in epilepsy in Han Chinese. Pharmacogenomics. 2009. Kwan Patrick, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
The clinical impact of pharmacogenetics on the treatment of epilepsy. Epilepsia. 2009. Löscher Wolfgang, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
No association of ABCB1 polymorphisms with drug-refractory epilepsy in a north Indian population. Epilepsy & behavior : E&B. 2009. Lakhan R, et al. PubMed
Carbamazepine and phenytoin induced Stevens-Johnson syndrome is associated with HLA-B*1502 allele in Thai population. Epilepsia. 2008. Locharernkul Chaichon, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
Phenytoin toxicity due to genetic polymorphism. Neurocritical care. 2009. McCluggage Lauren K, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Functional pharmacogenetics/genomics of human cytochromes P450 involved in drug biotransformation. Analytical and bioanalytical chemistry. 2008. Zanger Ulrich M, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
Multidrug resistance in epilepsy and polymorphisms in the voltage-gated sodium channel genes SCN1A, SCN2A, and SCN3A: correlation among phenotype, genotype, and mRNA expression. Pharmacogenetics and genomics. 2008. Kwan Patrick, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
HLA-B locus in Japanese patients with anti-epileptics and allopurinol-related Stevens-Johnson syndrome and toxic epidermal necrolysis. Pharmacogenomics. 2008. Kaniwa Nahoko, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Structure, function and regulation of P-glycoprotein and its clinical relevance in drug disposition. Xenobiotica; the fate of foreign compounds in biological systems. 2008. Zhou S-F. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Capecitabine: an overview of the side effects and their management. Anti-cancer drugs. 2008. Saif Muhammad Wasif, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Functional evaluation of polymorphisms in the human ABCB1 gene and the impact on clinical responses of antiepileptic drugs. Pharmacogenetics and genomics. 2008. Hung Chin-Chuan, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Stevens-Johnson syndrome and toxic epidermal necrolysis: assessment of medication risks with emphasis on recently marketed drugs. The EuroSCAR-study. The Journal of investigative dermatology. 2008. Mockenhaupt Maja, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available VA No VIP available No VIP available
HLA-B allele associations with certain drugs are not confirmed in Japanese patients with severe cutaneous drug reactions. Acta dermato-venereologica. 2008. Kano Yoko, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Stereoselective glucuronidation of 5-(4'-hydroxyphenyl)-5-phenylhydantoin by human UDP-glucuronosyltransferase (UGT) 1A1, UGT1A9, and UGT2B15: effects of UGT-UGT interactions. Drug metabolism and disposition: the biological fate of chemicals. 2007. Nakajima Miki, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
Therapeutic drug monitoring and clinical outcomes in epileptic Egyptian patients: a gene polymorphism perspective study. Therapeutic drug monitoring. 2007. Ebid Abdel-Hameed I Mohammed, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Relative activation of human pregnane X receptor versus constitutive androstane receptor defines distinct classes of CYP2B6 and CYP3A4 inducers. The Journal of pharmacology and experimental therapeutics. 2007. Faucette Stephanie R, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
A common polymorphism in the SCN1A gene associates with phenytoin serum levels at maintenance dose. Pharmacogenetics and genomics. 2006. Tate Sarah K, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
Paradoxical urinary phenytoin metabolite (S)/(R) ratios in CYP2C19*1/*2 patients. Epilepsy research. 2006. Argikar Upendra A, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Tamoxifen inhibits cytochrome P450 2C9 activity in breast cancer patients. Journal of chemotherapy (Florence, Italy). 2006. Boruban M C, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
ABCB1 polymorphisms influence the response to antiepileptic drugs in Japanese epilepsy patients. Pharmacogenomics. 2006. Seo Takayuki, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Evaluation of 170 xenobiotics as transactivators of human pregnane X receptor (hPXR) and correlation to known CYP3A4 drug interactions. Current drug metabolism. 2006. Sinz Michael, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
P450 2C18 catalyzes the metabolic bioactivation of phenytoin. Chemical research in toxicology. 2005. Kinobe Robert T, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Defining the clinical role of pharmacogenetics in antiepileptic drug therapy. The pharmacogenomics journal. 2006. Dlugos D J, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
CYP2C9, CYP2C19, ABCB1 (MDR1) genetic polymorphisms and phenytoin metabolism in a Black Beninese population. Pharmacogenetics and genomics. 2005. Allabi Aurel C, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Phenobarbital and phenytoin increased acetaminophen hepatotoxicity due to inhibition of UDP-glucuronosyltransferases in cultured human hepatocytes. Toxicological sciences : an official journal of the Society of Toxicology. 2005. Kostrubsky Seva E, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
Genetic predictors of the maximum doses patients receive during clinical use of the anti-epileptic drugs carbamazepine and phenytoin. Proceedings of the National Academy of Sciences of the United States of America. 2005. Tate Sarah K, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
RLIP76, a non-ABC transporter, and drug resistance in epilepsy. BMC neuroscience. 2005. Awasthi Sanjay, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Phenytoin may increase the efficacy of temozolomide by methylating DNA-repair enzyme, O6-methylguanine-DNA methyltransferase in patients with glioblastoma. Medical hypotheses. 2005. Altundag Ozden, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
Dosage recommendation of phenytoin for patients with epilepsy with different CYP2C9/CYP2C19 polymorphisms. Therapeutic drug monitoring. 2004. Hung Chin-Chuan, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
Genetic polymorphism of cytochrome P450 2C9 in diphenylhydantoin-induced cutaneous adverse drug reactions. European journal of clinical pharmacology. 2004. Lee Ai-Young, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
CYP2C polymorphisms, phenytoin metabolism and gingival overgrowth in epileptic subjects. Life sciences. 2004. Soga Yoshihiko, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Clinical relevance of genetic polymorphisms in the human CYP2C9 gene. European journal of clinical investigation. 2003. Schwarz U I. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
Severe intoxication after phenytoin infusion: a preventable pharmacogenetic adverse reaction. Neurology. 2003. Citerio G, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Involvement of multiple UDP-glucuronosyltransferase 1A isoforms in glucuronidation of 5-(4'-hydroxyphenyl)-5-phenylhydantoin in human liver microsomes. Drug metabolism and disposition: the biological fate of chemicals. 2002. Nakajima Miki, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Inhibitory effects of tricyclic antidepressants (TCAs) on human cytochrome P450 enzymes in vitro: mechanism of drug interaction between TCAs and phenytoin. Drug metabolism and disposition: the biological fate of chemicals. 2002. Shin Jae-Gook, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Evaluation of potential losartan-phenytoin drug interactions in healthy volunteers. Clinical pharmacology and therapeutics. 2002. Fischer Tracy L, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
CYP3A4 induction by drugs: correlation between a pregnane X receptor reporter gene assay and CYP3A4 expression in human hepatocytes. Drug metabolism and disposition: the biological fate of chemicals. 2002. Luo Gang, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Cytochrome P450 2C9 polymorphisms: a comprehensive review of the in-vitro and human data. Pharmacogenetics. 2002. Lee Craig R, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Identification of a null allele of CYP2C9 in an African-American exhibiting toxicity to phenytoin. Pharmacogenetics. 2001. Kidd R S, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Med-psych drug-drug interactions update. Psychosomatics. 2002. Armstrong Scott C, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
Severe phenytoin intoxication in a subject homozygous for CYP2C9*3. Clinical pharmacology and therapeutics. 2001. Brandolese R, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
Phenytoin metabolic ratio: a putative marker of CYP2C9 activity in vivo. Pharmacogenetics. 2001. Caraco Y, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
The effect of genetic polymorphism of cytochrome P450 CYP2C9 on phenytoin dose requirement. Pharmacogenetics. 2001. van der Weide J, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Formation of a dihydroxy metabolite of phenytoin in human liver microsomes/cytosol: roles of cytochromes P450 2C9, 2C19, and 3A4. Drug metabolism and disposition: the biological fate of chemicals. 2000. Komatsu T, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
Phenytoin metabolism by human cytochrome P450: involvement of P450 3A and 2C forms in secondary metabolism and drug-protein adduct formation. Drug metabolism and disposition: the biological fate of chemicals. 2000. Cuttle L, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
Genetic polymorphism of the CYP2C subfamily and excessive serum phenytoin concentration with central nervous system intoxication. Therapeutic drug monitoring. 2000. Ninomiya H, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
Frequency of cytochrome P450 CYP2C9 variants in a Turkish population and functional relevance for phenytoin. British journal of clinical pharmacology. 1999. Aynacioglu A S, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
The effects of genetic polymorphisms of CYP2C9 and CYP2C19 on phenytoin metabolism in Japanese adult patients with epilepsy: studies in stereoselective hydroxylation and population pharmacokinetics. Epilepsia. 1998. Mamiya K, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Free radical intermediates of phenytoin and related teratogens. Prostaglandin H synthase-catalyzed bioactivation, electron paramagnetic resonance spectrometry, and photochemical product analysis. The Journal of biological chemistry. 1998. Parman T, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Non-monooxygenase cytochromes P450 as potential human autoantigens in anticonvulsant hypersensitivity reactions. Pharmacogenetics. 1998. Leeder J S, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Inhibition of human hepatic cytochrome P4502E1 by azole antifungals, CNS-active drugs and non-steroidal anti-inflammatory agents. Xenobiotica; the fate of foreign compounds in biological systems. 1998. Tassaneeyakul W, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Phenytoin-induced depletion of folate in rats originates in liver and involves a mechanism that does not discriminate folate form. The Journal of nutrition. 1997. Carl G F, et al. PubMed
No Dosing Guideline available No Drug Label available CA VA No VIP available No VIP available
Genetic polymorphism of the CYP2C subfamily and its effect on the pharmacokinetics of phenytoin in Japanese patients with epilepsy. Clinical pharmacology and therapeutics. 1997. Odani A, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Roles of cytochrome P4502C9 and cytochrome P4502C19 in the stereoselective metabolism of phenytoin to its major metabolite. Drug metabolism and disposition: the biological fate of chemicals. 1996. Bajpai M, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Interindividual variations in human liver cytochrome P-450 enzymes involved in the oxidation of drugs, carcinogens and toxic chemicals: studies with liver microsomes of 30 Japanese and 30 Caucasians. The Journal of pharmacology and experimental therapeutics. 1994. Shimada T, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Prenatal prediction of risk of the fetal hydantoin syndrome. The New England journal of medicine. 1990. Buehler B A, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Influence of phenytoin and phenobarbital on the disposition of a single oral dose of clonazepam. Clinical pharmacology and therapeutics. 1980. Khoo K C, et al. PubMed
No Dosing Guideline available No Drug Label available No Clinical Annotation available VA No VIP available No VIP available
Drug-induced haemolysis in glucose-6-phosphate dehydrogenase deficiency. British medical journal. 1976. Chan T K, et al. PubMed

LinkOuts

Web Resource:
Wikipedia
National Drug Code Directory:
51672-4069-1
DrugBank:
DB00252
ChEBI:
8107
KEGG Compound:
C07443
KEGG Drug:
D00512
PubChem Compound:
1775
PubChem Substance:
148821
46508847
IUPHAR Ligand:
2624
Drugs Product Database (DPD):
780626
ChemSpider:
1710
Therapeutic Targets Database:
DAP000130
FDA Drug Label at DailyMed:
093fd736-5971-47af-b4ef-08c1696cebe8

Clinical Trials

These are trials that mention phenytoin and are related to either pharmacogenetics or pharmacogenomics.

No trials found.

Common Searches

Search PubMed
Search Medline Plus
Search PubChem
Search CTD

Sources for PharmGKB drug information: DrugBank, PubChem.