Drug Groups

approved

Description

A histamine congener, it competitively inhibits histamine binding to histamine H2 receptors. Cimetidine has a range of pharmacological actions. It inhibits gastric acid secretion, as well as pepsin and gastrins output. It also blocks the activity of cytochrome P-450 which might explain proposals for use in neoadjuvant therapy. [PubChem]

Indication

For the treatment and the management of acid-reflux disorders (GERD), peptic ulcer disease, heartburn, and acid indigestion.

Pharmacology

Cimetidine is a histamine H₂-receptor antagonist. It reduces basal and nocturnal gastric acid secretion and a reduction in gastric volume, acidity, and amount of gastric acid released in response to stimuli including food, caffeine, insulin, betazole, or pentagastrin. It is used to treat gastrointestinal disorders such as gastric or duodenal ulcer, gastroesophageal reflux disease, and pathological hypersecretory conditions. Cimetidine inhibits many of the isoenzymes of the hepatic CYP450 enzyme system. Other actions of Cimetidine include an increase in gastric bacterial flora such as nitrate-reducing organisms.

Toxicity

Symptoms of overdose include nausea, vomiting, diarrhea, increased saliva production, difficulty breathing, and a fast heartbeat.

Affected Organisms

Biotransformation

Hepatic

Absorption

Rapid 60-70%

Half Life

2 hours

Protein Binding

15-20%

Elimination

The principal route of excretion of cimetidine is the urine.

References

External Links