Effects of Nocloprost on Gastric Functions in Man

Abstract

Previous studies in animals and humans demonstrated that nocloprost, a stable prostaglandin E₂ analogue, shows very high gastroprotective potency, relatively weak gastric inhibitory activity, and low systemic bioavailability after oral administration. In this study the effects of nocloprost on gastric acid secretion and intraluminal pH and on gastric emptying and plasma gastrin levels were determined in humans. Nocloprost at doses of 50 and 100 μg was ineffective, but at a dose of 200 μg it reduced the response to pentagastrin significantly and that to a peptone meal by 30–50% and abolished plasma gastrin response without affecting the rate of gastric emptying. Nocloprost given at a dose of 100 μg three times daily 30 min before the major meals (breakfast, lunch, and dinner) did not affect intragastric pH significantly as monitored by continuous intraluminal pH-metry. We conclude that nocloprost does not affect gastric acid secretion or intraluminal pH when applied at a dose (50–100 μg) that is gastroprotective and that is proposed for peptic ulcer therapy. A higher dose (200 μg) of nocloprost causes moderate gastric acid inhibition and suppression of plasma gastrin release without affecting gastric emptying or causing any side effects.

Key Words:

• Gastric emptying
• gastrin
• prostaglandin
• stomach