Zaltidine(CP-57361) is a H2-receptor antagonist, which has the antisecretory action.IC50 Value: Target: H2 receptorin vitro:in vivo: In eight healthy male volunteers single oral doses of 5 mg, 25 mg and 100 mg produced dose-related inhibition of basal and pentagastrin-stimulated acid output (M.A.O.) with an estimated ID50 of 40 mg for the latter. In eight subjects with duodenal ulceration single 100 mg and 200 mg doses produced 85% and 97% inhibition of M.A.O. at peak (3 h post-dose) and 20% and 23% inhibition at 24 h, respectively; inhibition of basal acid output was 97% at 3 h and 50% at 24 h with both doses [1]. One hundred and thirty-five patients were randomly allocated to 4 weeks' treatment with either 150 mg zaltidine once daily or placebo. Fifty-nine were treated for a full 4 weeks with zaltidine before the trial was stopped. Healing rates after 4 weeks of zaltidine and placebo were 86% and 19%, respectively (p less than 0.001) [2].

[1]. Laferla G, Buchanan N, Hearns J, The antisecretory effects of zaltidine, a novel long-acting H2-receptor antagonist, in healthy volunteers and in subjects with a past history of duodenal ulcer. Br J Clin Pharmacol. 1986 Oct;22(4):395-9. [2]. Farup PG. Zaltidine: an effective but hepatotoxic H2-receptor antagonist. Scand J Gastroenterol. 1988 Aug;23(6):655-8.