Products
Famotidine is not commercially available in many countries. In Germany and other countries, it is available in the form of film-coated tablets.
Structure and properties
Famotidine (C8H15N7O2S3, Mr = 337.4 g/mol) exists as a white to yellowish-white crystalline powder or as crystals and is very sparingly soluble in water. It is a thiazole derivative and an organic cation that is eliminated and secreted mainly by the kidney.
Effects
Famotidine (ATC A02BA03) inhibits the secretion of gastric acid and pepsin in the stomach. Effects are due to selective antagonism at histamine H2 receptors. Effects occur after about one hour and last for 12 hours.
Indications
For the treatment of gastric and intestinal ulcers and Zollinger-Ellison syndrome. Off-Label Use: In 2020, famotidine was investigated for the treatment of coronavirus disease Covid-19.
Dosage
According to the SmPC. Tablets are taken once or twice daily and independent of meals.
Contraindications
- Hypersensitivity
For complete precautions, see the drug label.
Interactions
Alteration of gastric pH may affect the absorption and bioavailability of other drugs. Antacids should not be taken concurrently but should be spaced 1 to 2 hours apart. Probenecid may decrease excretion. Famotidine does not interact with CYP450 and, unlike cimetidine, has a low interaction potential.
Adverse effects
The most common potential adverse effects include headache and dizziness.
