The Effects of Cimetidine on the Oxidative Metabolism of Estradiol

Abstract
Cimetidine, a histamine H2–receptor antagonist widely used to treat peptic ulceration, is known to cause gynecomastia and sexual dysfunction in some men. Since cimetidine inhibits the cytochrome P-450–dependent biotransformation of numerous drugs, we investigated the possibility that it might also inhibit the cytochrome P-450–dependent metabolism of estradiol.