Chemical Component Summary

FormulaC12 H22 O11
Molecular Weight342.30
Isomeric SMILESOC[C@H]1O[C@@H](O[C@@H]2[C@@H](CO)O[C@](O)(CO)[C@H]2O)[C@H](O)[C@@H](O)[C@H]1O

Chemical Details

Formal Charge0
Atom Count45
Chiral Atom Count9
Bond Count46
Aromatic Bond Count0

Drug Info: DrugBank

DrugBank IDDB00581 
DescriptionLactulose is a synthetic disaccharide derivative of lactose that is most commonly used as a laxative agent despite also being formally indicated to serve as an adjunct therapy in treating portal-systemic encephalopathy (PSE).[FDA Label,L6199,L6202] Despite being first synthesized in 1929[A178081], investigations regarding its possible use as a laxative for the treatment of chronic constipation did not occur until the 1960s and its first clinical use for treating PSE was not until 1966.[L6202] Nevertheless, although lactulose received formal FDA approval in 1977 and has since become a readily available generic and brand-name non-prescription medication listed on the World Health Organization's List of Essential Medicines as one of the most effective and safe medicines employed in a health system[L6205], data regarding its optimal place in therapy is often ambiguous.[L6202] Especially considering the use of lactulose as a laxative is typically only considered after lifestyle and dietary modifications fail and the fact that lactulose therapy cannot be ethically withheld from patients diagnosed with PSE in a placebo study, the substance may just be one of many options available for treating constipation and its efficacy in managing PSE may never be formally confirmed or refuted via clinical investigation.[L6202]
  • Lactulosa
  • 4-O-beta-D-Galactopyranosyl-D-fructofuranose
  • Lactulose
  • 4-O-beta-D-Galactopyranosyl-D-fructose
  • Lactulosum
Brand Names
  • PHL-lactulose Soln 667mg/ml
  • Duphalac
  • Enulose
  • Lactulose Solution USP - Liq 667mg/ml
  • Cephulac Syr 667mg/ml
IndicationLactulose is indicated for use as a laxative in the treatment of chronic constipation in adults and geriatric patients.[FDA Label,L6199,L6202] Additionally, lactulose is also employed as an adjunct to protein restriction and supportive therapy for the prevention and treatment of portal-systemic encephalopathy (PSE), including both the hepatic pre-coma and coma variations.[FDA Label,L6199,L6202] In particular, lactulose solution has been effective at managing PSE resulting from surgical portacaval shunts or from chronic hepatic diseases like cirrhosis.[L6199] Moreover, there have also been studies demonstrating the capacity for lactulose to minimize the formation of gallstones and even some investigations regarding the experimental use of the agent in developing novel anticancer agents owing to its ability to bind galactin carbohydrates involved in various tumor progressions [L6202].
  • Acidifying Activity
  • Alimentary Tract and Metabolism
  • Ammonia Detoxicants
  • Carbohydrates
  • Disaccharides
  • A06AD61
  • A06AD11
CAS number4618-18-2

Drug Targets

NameTarget SequencePharmacological ActionActions
Evolved beta-galactosidase subunit alphaMNRWENIQLTHENRLAPRAYFFSYDSVAQARTFARETSSLFLPLSGQWNF...unknownother
Drug Info/Drug Targets: DrugBank 3.0: a comprehensive resource for 'omics' research on drugs. Knox C, Law V, Jewison T, Liu P, Ly S, Frolkis A, Pon A, Banco K, Mak C, Neveu V, Djoumbou Y, Eisner R, Guo AC, Wishart DS. Nucleic Acids Res. 2011 Jan; 39 (Database issue):D1035-41. | PMID:21059682