Cimetidine (brand name: Tagamet) is a kind of histamine H2 receptor antagonist being capable of inhibiting the production of stomach acid, which reduces the gastric volume and acidity. It is mainly used for the treatment of heartburn and peptic ulcers. There are also evidences that it can be used for the treatment of common warts, chronic calcific tendinitis of the shoulder, and even colorectal cancer. It is capable of not only inhibiting the gastric acid secretion, as well as pepsin and gastrins output, but also inhibiting the activity of cytochrome P450. It reduces the gastric acid secretion through binding to the H2 receptor locating on the basolateral membrane of the gastric parietal cell, and further blocking histamine effect.
