cimetidine

Also known as cimetidine HCl, Tagamet®, 1-Cyano-2-methyl-3-(2-(((5-methyl-4-imidazolyl)methyl)thio)ethyl)guanidine, N''-cyano-N-methyl-N'-(2-{[(5-methyl-1H-imidazol-4-yl)methyl]thio}ethyl)guanidine, N-cyano-N'-methyl-N''-(2-([(5-methyl-1H-imidazol-4-yl)methyl]sulfanyl)ethyl)guanidine,

Key facts

Drug.pregnancy_AU: B1
Drug.routes_of_administration: By mouth, intramuscular injection, intravenous infusion
Drug.ATC_prefix: A02
Drug.ATC_suffix: BA01
Drug.legal_AU: S4
Drug.legal_UK: POM
Drug.legal_US: Rx-only
Drug.legal_US_comment: / OTC
Drug.bioavailability: 60–70%
Drug.protein_bound: 13–25%
Drug.metabolism: Liver
Drug.Watchedfields: changed
Drug.verifiedrevid

~17 min read

Article

16 sections

Contents

Medical uses
Side effects
Overdose
Interactions
Pharmacology
Pharmacodynamics
Histamine H<sub>2</sub> receptor antagonism
Cytochrome P450 inhibition
Antiandrogenic and estrogenic effects
Pharmacokinetics
History
Lawsuit
Research
Veterinary use
References
External links

Cimetidine, sold under the brand name Tagamet among others, is a histamine H2 receptor antagonist that inhibits stomach acid production. It is mainly used in the treatment of heartburn and peptic ulcers.

With the development of proton pump inhibitors, such as omeprazole, approved for the same indications, cimetidine is available as an over-the-counter formulation to prevent heartburn or acid indigestion, along with the other H2-receptor antagonists.