Pharmacology
Famotidine is a competitive inhibitor of histamine H2-receptors. The primary clinically important pharmacologic activity of Famotidine is inhibition of gastric secretion. Both the acid concentration and volume of gastric secretion are suppressed by Famotidine, while changes in pepsin secretion are proportional to volume output. In normal volunteers and hypersecretors, famotidine inhibited basal and noctural gastric secretion, as well as secretion stimulated by food and pentagastrin, After oral administration. The onset of the antisecretory effect occured within one hour; the maximum effect was dose-dependent, occuring within one to three hours. Duration of inhibition of secretion by doses of 20 mg and 40 mg was 10 to 12 hours.
Pharmacokinetics
Famotidine is incompletely absorbed. The bioavailability of oral doses is 40-45%. After oral doses, peak plasma level occur in 1-3 hours. Plasma levels after multiple doses are similar to those after single doses. 15 to 20 % of Famotidine in plasma is protein bound. Famotidine has an elimination half-life of 2.5 -3.5 hours, eliminated by renal (65-70%) and metabolic (30-35%).
Indications:
- Maintenance therapy and treatment of duodenal ulcer
- Treatment of gastroesophageal reflux
- Active benign gastric ulcer
- Pathological hypersecretory conditions
Side Effects:
The H2 blockers as a group have a very limited potential for side effects. but there have been some reports of exacerbating heart rhythm problems in patients who already have heart rhythm problems so it may be prudent to choose another means of stomach acid control in heart patients.
The most common presentations:
- Famotidine Tablets ( 10 mg, 20 mg, 40 mg)
- Famotidine Injection 10 mg/mL
- Famotidine Infusion
