Description

Simple

A medication used to treat acid reflux, stomach ulcers, and indigestion.

Clinical

A histamine H2 receptor antagonist used to manage GERD, peptic ulcer disease, and indigestion.

Overview

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.

Pharmacology

Indication

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

Pharmacodynamic

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... Read more

Mechanism of action

Cimetidine binds to an H2-receptor located on the basolateral membrane of the gastric parietal cell, blocking histamine effects. This competitive inhibition results in reduced gastric acid secretion and a reduction in gastric volume and acidity.

Absorption

Rapid 60-70%

Protein binding

15-20%

Volume of distribution

Information currently not available.

Clearance

Information currently not available.

Half life

2 hours

Route of elimination

The principal route of excretion of cimetidine is the urine.

Toxicity

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

Adverse Effects

Contraindications

Information currently not available.

Food Interactions

  • Avoid alcohol.
  • Best effect when taken with food.
  • Limit caffeine intake.

Interactions

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  • Paracetamol(acetaminophen)
  • Paxil(paroxetine)
  • Pamelor(nortriptyline)
  • Panadol(acetaminophen)
  • Patanol(olopatadine ophthalmic)
  • Pataday(olopatadine ophthalmic)
  • Parnate(tranylcypromine)
  • Pazeo(olopatadine ophthalmic)
(R)-warfarin
The serum concentration of (R)-warfarin can be increased when it is combined with Cimetidine.
(S)-Warfarin
The serum concentration of (S)-Warfarin can be increased when it is combined with Cimetidine.
2,5-Dimethoxy-4-ethylamphetamine
2,5-Dimethoxy-4-ethylamphetamine may decrease the sedative and stimulatory activities of Cimetidine.
2,5-Dimethoxy-4-ethylthioamphetamine
2,5-Dimethoxy-4-ethylthioamphetamine may decrease the sedative and stimulatory activities of Cimetidine.
3-isobutyl-1-methyl-7H-xanthine
The metabolism of 3-isobutyl-1-methyl-7H-xanthine can be decreased when combined with Cimetidine.
4-Bromo-2,5-dimethoxyamphetamine
4-Bromo-2,5-dimethoxyamphetamine may decrease the sedative and stimulatory activities of Cimetidine.
4-hydroxycoumarin
The metabolism of 4-hydroxycoumarin can be decreased when combined with Cimetidine.
4-Methoxyamphetamine
The metabolism of 4-Methoxyamphetamine can be decreased when combined with Cimetidine.
5-fluorouridine
The serum concentration of 5-fluorouridine can be increased when it is combined with Cimetidine.
5-methoxy-N,N-dimethyltryptamine
The metabolism of 5-methoxy-N,N-dimethyltryptamine can be decreased when combined with Cimetidine.
6-O-benzylguanine
The metabolism of 6-O-benzylguanine can be decreased when combined with Cimetidine.
7-Deazaguanine
The metabolism of 7-Deazaguanine can be decreased when combined with Cimetidine.
7,9-Dimethylguanine
The metabolism of 7,9-Dimethylguanine can be decreased when combined with Cimetidine.
8-azaguanine
The metabolism of 8-azaguanine can be decreased when combined with Cimetidine.
8-chlorotheophylline
The metabolism of 8-chlorotheophylline can be decreased when combined with Cimetidine.
9-aminocamptothecin
The metabolism of 9-aminocamptothecin can be decreased when combined with Cimetidine.
9-Deazaguanine
The metabolism of 9-Deazaguanine can be decreased when combined with Cimetidine.
9-Methylguanine
The metabolism of 9-Methylguanine can be decreased when combined with Cimetidine.
Abacavir
Cimetidine may decrease the excretion rate of Abacavir which could result in a higher serum level.
Abafungin
Cimetidine can cause a decrease in the absorption of Abafungin resulting in a reduced serum concentration and potentially a decrease in efficacy.
1 References
  1. 1 . Michnovicz JJ, Galbraith RA: Cimetidine inhibits catechol estrogen metabolism in women. Metabolism. 1991 Feb;40(2):170-4.PubMed: 1988774