Comparison of antisecretory potency and duration of action of the H2-receptor antagonists AH 22216, cimetidine, ranitidine and SK & F 93479 in the dog.

The antisecretory potency and duration of action of the new histamine H2-receptor antagonist AH 22216 have been compared with those of cimetidine, ranitidine and SK & F 93479 against histamine-induced gastric acid secretion in the conscious Heidenhain pouch dog. Ranitidine was 4-6 times more potent than cimetidine, with a similar duration of action. SK & F 93479 was approximately twice as potent as ranitidine and had a slightly longer duration of action. AH 22216 was most potent of the four H2-antagonists, some 20-30 times more active than cimetidine, and had an extremely prolonged duration of action.