Famotack 40 mg is a film-coated tablet containing 40 mg of Famotidine, a histamine H₂-receptor antagonist. It works by inhibiting the action of histamine on H₂-receptors in the stomach's parietal cells, thereby reducing gastric acid secretion. This mechanism helps in the treatment and prevention of conditions such as gastric and duodenal ulcers, gastroesophageal reflux disease (GERD), and Zollinger-Ellison syndrome.