Cimetidine, also known as metformin, is an organic compound with the chemical formula C10H16N6S. It is a histamine H2 receptor impedance agent mainly used to inhibit the secretion of gastric acid. It can significantly inhibit basal and nocturnal gastric acid secretion, as well as inhibit gastric acid secretion caused by histamine, peptide gastrin, insulin, and food stimuli, and reduce its acidity. It has a preventive and protective effect on corrosive gastritis caused by chemical stimuli, It also has significant therapeutic effects on stress-induced gastric ulcers and upper gastrointestinal bleeding.
On October 27, 2017, the International Agency for Research on Cancer of the World Health Organization released a preliminary list of carcinogens for reference, and cimetidine was listed as one of the three carcinogens in the list