Overview
| Generic Names: | Carboxyterfenadine; Fexofenadine hydrochloride; Fexofendine; Terfenadine acid metabolite; Terfenadine carboxylate; Terfenadine-COOH |
|---|---|
| IUPAC Name: | 2-[4-[1-hydroxy-4-[4-[hydroxy-di(phenyl)methyl]piperidin-1-yl]butyl]phenyl]-2-methylpropanoic acid |
| Trade Names: | Allegra |
| Brand Mixtures: | Allegra-D (Fexofenadine hydrochloride + Pseudoephedrine hydrochloride) |
| PharmGKB Accession Id: | PA449621 |
Description
Fexofenadine hydrochloride (Allegra) is an antihistamine drug used in the treatment of hayfever and similar allergy symptoms. It was developed as a successor of and alternative to terfenadine. Fexofenadine, like other second and third-generation antihistamines, does not readily pass through the blood-brain barrier, and so causes less drowsiness than first-generation histamine-receptor antagonists.
Indication
For management of Seasonal allergic rhinitis
ATC Therapeutic Category
- R06AX:Other antihistamines for systemic use
Pharmacology and Interactions
Mechanism Of Action
Like other H1-blockers, Fexofenadine competes with free histamine for binding at H1-receptors in the GI tract, large blood vessels, and bronchial smooth muscle. This blocks the action of endogenous histamine, which subsequently leads to temporary relief of the negative symptoms brought on by histamine. Fexofenadine exhibits no anticholinergic, alpha1-adrenergic or beta-adrenergic-receptor blocking effects.
Pharmacology
Fexofenadine is a second-generation, long lasting H1-receptor antagonist (antihistamine) which has a selective and peripheral H1-antagonist action. Histamine is a chemical that causes many of the signs that are part of allergic reactions, for example, swelling of tissues. Histamine is released from histamine-storing cells (mast cells) and attaches to other cells that have receptors for histamine. The attachment of the histamine to the receptors causes the cell to be "activated," releasing other chemicals which produce the effects that we associate with allergy. Fexofenadine blocks one type of receptor for histamine (the H1 receptor) and thus prevents activation of cells by histamine. Unlike most other antihistamines, Fexofenadine does not enter the brain from the blood and, therefore, does not cause drowsiness. Fexofenadine lacks the cardiotoxic potential, since it does not block the potassium channel involved in repolarization of cardiac cells.
Food Interactions
Grapefruit and grapefruit juice should be avoided throughout treatment as grapefruit can significantly decrease serum levels of this product. Take without regard to meals.
Absorption, Distribution, Metabolism, Elimination & Toxicity
Biotransformation
Approximately 5% of the total dose is metabolized, by cytochrome P450 3A4 and by intestinal microflora.
Protein Binding
60%-70%
Absorption
33%
Half Life
14.4 hours
Toxicity
Side effects include dizziness, drowsiness, and dry mouth.
Chemical Properties
Chemical Formula:
C32H39NO4
SMILES Code:
CC(C)(C1=CC=C(C=C1)[C@@H](CCCN2CCC(CC2)C(C3=CC=CC=C3)(C4=CC=CC=C4)O)O)C(=O)O
(Format: OpenEye Isomeric)
Molecular Weight ( average / monoisotopic )
501.6564 / 501.2879
In-Depth Annotations (
)
-
rs1045642
at chr7:86976581
in
ABCB1
3435TT homozygotes showed statistically different fenofexadine area under the concentration curve (AUC) values for 0-4 hours (p = 0.036) than CC homozygotes.- Variant Name:
- ABCB1:3435C>T (ABCB1:3853C>T (dbSNP build 130))
- Related Drugs:
- fexofenadine
- Evidence:
-
PMID:11503014
-
rs2032582
at chr7:86998554
in
ABCB1
893Ser-expressing (ABCB1:2677G>T (Ala893Ser)) cells showed 47% lower intracellular digoxin concentration (p < .002) than Ala893-expressing cells; and 893Ser/Ser homozygotes showed statistically different fenofexadine area under the concentration curve (AUC) values for 0-4 hours (p = 0.054) than 893Ala/Ala homozygotes.- Variant Name:
- ABCB1:2677G>T/A (ABCB1:3095G>T/A (dbSNP build 130)) (Ala893Ser/Thr)
- Related Drugs:
- digoxin, fexofenadine
- Evidence:
-
PMID:11503014
Curated Information
The following genes are in curated knowledge about this drug.
| Gene | Relationship | Evidence | |
|---|---|---|---|
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ABCB1 |
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Publications, Variants |
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CYP3A4 |
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Publications |
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SLCO1A2 |
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Publications |
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SLCO1B1 |
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Publications |
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SLCO1B3 |
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Publications |
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SLCO2B1 |
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Publications |
Non-Curated Information
A list of non-curated publications that mention this drug along with other genes is available.
Metabolizing Enzymes
Drug Targets
Non-Curated Information
A list of non-curated publications that mention this drug along with other drugs is available.
Drug Interactions
| cisapride | Increased risk of cardiotoxicity and arrhythmias |
Non-Curated Information
A list of non-curated publications that mention this drug along with other diseases is available.
LinkOuts
Common Searches
Search PubMed
Search Medline Plus
Search PubChem
Search CTD
Non-Curated Publications
A list of non-curated publications that mention this drug is available.