Dose-dependent gastrointestinal effects of the somatostatin analog lanreotide in healthy volunteers

Objective: To investigate the gastrointestinal effects of intravenous lanre otide. Methods: Twenty healthy male subjects participated in 2 subsequent placebo- controlled, double-blind crossover studies. The effects of 3 doses of lanre otide (50, 100, and 200 mu g/h) were investigated on 24-hour intragastric a cidity (study I), food-stimulated gallbladder contraction, and plasma chole cystokinin release (study II). Results: Lanreotide showed linear pharmacokinetics. It raised median intrag astric pH significantly and in a dose-dependent manner: from 1.4 +/- 0.2 (p lacebo) to 2.5 +/- 0.8 (P < .002) during administration of 50 mu g/h lanreo tide, to 3.2 +/- 0.7 (P < .001) during 100 mu g/h lanreotide, and to 4.3 +/ - 0.7 (P < .001) during 200 mu g/h lanreotide. However, no significant inhi bition of gastrin secretion could be established. All doses completely inhi bited postprandial gallbladder contraction, Conclusion: Intravenous administration of lanreotide at rates applied in th is study was able to significantly inhibit intragastric acid secretion and postprandial gallbladder contraction; under these conditions few untoward e ffects were noted.