Description
Mechanism of Action
Cimetidine competitively inhibits histamine at H2-receptors of the gastric parietal cells resulting in decreased gastric acid secretion, gastric volume and hydrogen ion concentration. It is also used in patients w/ pancreatic insufficiency to reduce the breakdown of pancreatic enzyme supplements.
Onset: 1 hr.
Duration: 4-5 hr.
Absorption: Readily absorbed from the GI tract. Food delays the rate and slightly decreases extent of absorption. Bioavailability: Approx 60-70%. Time to peak plasma concentration: Approx 1-3 hr.
Distribution: Widely distributed; enters breast milk, crosses the placental barrier. Volume of distribution: Approx 1 L/kg. Plasma protein binding: Approx 20%.
Metabolism: Partially hepatic, converted to sulfoxide and hydroxymethylcimetidine.
Excretion: Via urine (oral: approx 50%, IV: 75%) as unchanged drug. Elimination half-life: Approx 2 hr.
MIMS Class
Antacids, Antireflux Agents & Antiulcerants
ATC Classification
A02BA01 – cimetidine; Belongs to the class of H2-receptor antagonists. Used in the treatment of peptic ulcer and gastro-oesophageal reflux disease (GERD).;
