Influence of RP 40749 on basal and meal-stimulated serum-gastrin, serum-pepsinogen I, and gastrin-content of the antral mucosa in duodenal ulcer patients.

Eighteen patients with active duodenal ulcer were treated with a novel antisecretory drug, RP 40749, either 100 mg or 150 mg as a daily nocturnal dose for 28 days. In these patients we evaluated the clinical course, endoscopic healing rates after 28 days, routine laboratory parameters, basal serum gastrin and pepsinogen I levels, meal-stimulated serum gastrin concentration, and the gastrin content of the antral mucosa. All nine patients receiving 150 mg RP 40749 and eight of nine patients receiving 100 mg RP 40749 healed their ulcers completely within 28 days, becoming rapidly symptom-free after an average of three days. The basal (53.8 +/- 5.2 vs 99.8 +/- 11.4 pg/ml) and meal-stimulated serum gastrin levels (109.2 +/- 12.1 vs 189.2 +/- 16.7 pg/ml) rose significantly after treatment with RP 40749, as did the gastrin content of the antral mucosa (11.3 +/- 2.1 vs 26.0 +/- 5.1 micrograms/g), suggesting increased synthesis and secretion of gastrin. Between the 100 mg and 150 mg groups, no significant differences in response were observed. Serum pepsinogen I levels (64.9 +/- 7.3 vs 147.9 +/- 17.9 ng/ml) increased after treatment; the increase after 150 mg RP 40749 was significantly greater than that after 100 mg RP 40749. The increase of serum pepsinogen levels are probably due to a spillover effect resulting from a blockade in exocrine secretion into the lumen. There were no relevant changes in routine laboratory parameters.