A review of the animal pharmacology of ranitidine--a new, selective histamine H2-antagonist.

The animal pharmacology and metabolism of ranitidine have been reviewed. Experiments using guinea-pig isolated right atrium and ileum preparations have shown that ranitidine is a selective, potent, and competitive histamine H2-receptor antagonist. In the conscious dog gastric acid secretion induced by histamine, pentagastrin, bethanechol and food was inhibited by ranitidine at doses 4 to 12 times lower than equi-effective doses of cimetidine. Ranitidine inhibited the formation of aspirin-induced gastric lesions, both in the presence and absence of gastric acid. Unlike cimetidine, ranitidine neither possessed anti-androgenic activity, nor did it inhibit the mixed function oxygenase metabolizing enzyme system in the liver. Ranitidine has been recommended for clinical trial in the treatment of peptic ulcer disease.