Serum gastrin levels before and after 6 weeks of cimetidine therapy in patients with duodenal ulcer.

Fasting serum gastrins were carried out at the beginning and end of a 6-week double-blind trial of cimetidine and placebo in 30 patients with duodenal ulcer. Cimetidine did not cause any significant change in fasting serum gastrin levels after 6 weeks of therapy.