Cimetidine CH3 CH2SCH2CH2N=CNHCH3 (also ranitidine,famotidine,nizatidine) HN一C三N H2-R antagonist A histamine H2-receptor antagonist that inhibits the production of acid in the stomach.It is largely used in the treatment of heartburn and peptic ulcers.Approved in 1976,it is marketed under the trade name Tagamet. Cimetidine is a known inhibitor of many isozymes of the cytochrome P450 enzyme system,specifically CYP1A2, CYP2C9,CYP2C19,CYP2D6,CYP2E1,and CYP3A4. This inhibition forms the basis of the numerous drug interactions that occur between cimetidine and other drugs.For example,cimetidine may decrease metabolism of some drugs.A histamine H2-receptor antagonist that inhibits the production of acid in the stomach. It is largely used in the treatment of heartburn and peptic ulcers. Approved in 1976, it is marketed under the trade name Tagamet. Cimetidine is a known inhibitor of many isozymes of the cytochrome P450 enzyme system, specifically CYP1A2, CYP2C9, CYP2C19, CYP2D6, CYP2E1, and CYP3A4. This inhibition forms the basis of the numerous drug interactions that occur between cimetidine and other drugs. For example, cimetidine may decrease metabolism of some drugs. Cimetidine (also ranitidine, famotidine, nizatidine) H2-R antagonist