A member of the class of guanidines that consists of guanidine carrying a methyl substituent at position 1, a cyano group at position 2 and a 2-{[(5-methyl-1H-imidazol-4-yl)methyl]sulfanyl}ethyl group at position 3. It is a H2-receptor antagonist that inhibits the production of acid in stomach. ChEBI: Cimetidine is a member of the class of guanidines that consists of guanidine carrying a methyl substituent at position 1, a cyano group at position 2 and a 2-{[(5-methyl-1H-imidazol-4-yl)methyl]sulfanyl}ethyl group at position 3. It is a H2-receptor antagonist that inhibits the production of acid in stomach. It has a role as a H2-receptor antagonist, a P450 inhibitor, an anti-ulcer drug, an analgesic and an adjuvant. It is a member of guanidines, a member of imidazoles, an aliphatic sulfide and a nitrile.