Drug/Small Molecule:
lactulose

PharmGKB contains no dosing guidelines for this drug/small molecule. To report known genotype-based dosing guidelines, or if you are interested in developing guidelines, click here.

PharmGKB has no annotated drug labels with pharmacogenomic information for this drug/small molecule. If you know of a drug label with PGx, send us a message.

PharmGKB contains no Clinical Variants that meet the highest level of criteria.

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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.

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This is a non-comprehensive list of genetic tests with pharmacogenetics relevance, typically submitted by the manufacturer and manually curated by PharmGKB. The information listed is provided for educational purposes only and does not constitute an endorsement of any listed test or manufacturer.

A more complete listing of genetic tests is found at the Genetic Testing Registry (GTR).

PGx Test Variants Assayed Gene?
2D structure from PubChem
provided by PubChem

Overview

Generic Names
Trade Names
  • Acilac
  • Bifiteral
  • Cephulac
  • Cholac
  • Chronulac
  • Constilac
  • Constulose
  • D-Lactulose
  • Duphalac
  • Enulose
  • Evalose
  • Fructofuranose
  • Generlac
  • Heptalac
  • Isolactose
  • Kristalose
  • Lactulosa [INN-Spanish]
  • Lactulosa [Spanish]
  • Lactulose [USAN:BAN:INN:JAN]
  • Lactulose, ~98%
  • Lactulosum [INN-Latin]
  • Lactulosum [Latin]
  • Laevolac
  • Lattulosio [Italian]
  • Laxilose
  • Portalac
Brand Mixture Names

PharmGKB Accession Id:
PA164748762

Description

A synthetic disaccharide used in the treatment of constipation and hepatic encephalopathy. It has also been used in the diagnosis of gastrointestinal disorders. (From Martindale, The Extra Pharmacopoeia, 30th ed, p887)

Source: Drug Bank

Indication

For the treatment of constipation and hepatic encephalopathy.

Source: Drug Bank

Other Vocabularies

Information pulled from DrugBank has not been reviewed by PharmGKB.

Pharmacology, Interactions, and Contraindications

Mechanism of Action

Lactulose is a synthetic sugar used in the treatment of constipation and liver disease. It consists of the monosaccharides fructose and galactose. In the colon, lactulose is broken down primarily to lactic acid, and also to small amounts of formic and acetic acids, by the action of via evolved-beta galactosidase from colonic bacteria, which results in an increase in osmotic pressure and slight acidification of the colonic contents. This in turn causes an increase in stool water content and softens the stool. In treating heptic diseases (hepatic encephalopathy) it is thought that lactulose draws out ammonia from the body in the same way that it draws out water into the colon.

Source: Drug Bank

Pharmacology

Therapeutically, lactulose has laxative and ammonia-detoxifying actions. In treating constipation lactulose metabolites draw water into the bowel, causing a cathartic effect through osmotic action.

Source: Drug Bank

Food Interaction

Take without regard to meals. Drink liberally.

Source: Drug Bank

Absorption, Distribution, Metabolism, Elimination & Toxicity

Biotransformation

Lactulose is completely metabolized in the colon by enteric bacteria, and no lactulose is excreted in the feces.

Source: Drug Bank

Absorption

Poorly absorbed from the gastrointestinal tract as no human enzyme that is capable of hydrolysis of this disaccharide is present in human gastrointestinal tissue.

Source: Drug Bank

Half-Life

1.7-2 hours

Source: Drug Bank

Toxicity

LD 50=18.2 g/kg (oral, rat). Side effects include diarrhea and resultant dehydration.

Source: Drug Bank

Route of Elimination

The primary route of elimination is fecal. Urinary excretion has been determined to be 3% or less and is essentially complete within 24 hours.

Source: Drug Bank

Chemical Properties

Chemical Formula

C12H22O11

Source: Drug Bank

Isomeric SMILES

C([C@@H]1[C@@H]([C@@H]([C@H]([C@@H](O1)O[C@@H]2[C@H](O[C@@]([C@H]2O)(CO)O)CO)O)O)O)O

Source: Drug Bank

OC[C@H]1O[C@](O)(CO)[C@@H](O)[C@@H]1O[C@@H]1O[C@H](CO)[C@H](O)[C@H](O)[C@H]1O

Source: Drug Bank

Canonical SMILES

OC[C@H]1O[C@]

Source: Drug Bank

Average Molecular Weight

342.2965

Source: Drug Bank

Monoisotopic Molecular Weight

342.116211546

Source: Drug Bank

Publications related to lactulose: 1

No Dosing Guideline available No Drug Label available No Clinical Annotation available No Variant Annotation available No VIP available No VIP available
Prediction of adverse drug reactions using decision tree modeling. Clinical pharmacology and therapeutics. 2010. Hammann F, et al. PubMed

LinkOuts

Web Resource:
Wikipedia
National Drug Code Directory:
0054-8486-16
DrugBank:
DB00581
ChEBI:
6359
KEGG Compound:
C07064
KEGG Drug:
D00352
PubChem Compound:
11333
PubChem Substance:
46506757
9276
Drugs Product Database (DPD):
690686
ChemSpider:
10856
FDA Drug Label at DailyMed:
183c0621-d058-4600-9345-2b01d66cb65a

Clinical Trials

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

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Sources for PharmGKB drug information: DrugBank, Open Eye Scientific Software.