Cimetidine blocks antacid-induced hypergastrinemia.

Area of Science:

• Gastroenterology
• Pharmacology

Background:

• Antacids are commonly used to treat acid-related gastrointestinal disorders.
• The impact of antacids on serum gastrin levels, particularly in patients with duodenal ulcer disease, requires further elucidation.

Purpose of the Study:

• To investigate the effect of magnesium and aluminum hydroxide antacid on fasting serum gastrin concentrations.
• To determine the role of intravenous cimetidine in modulating antacid-induced gastrin level changes.

Main Methods:

• Eight patients with duodenal ulcer disease received hourly doses of magnesium and aluminum hydroxide antacid.
• Serum gastrin concentrations were measured over 10 hours, with and without simultaneous intravenous cimetidine administration.
• Gastric pH was monitored, and sodium bicarbonate was used as a control.

Main Results:

• Antacid administration, either as a bolus or infusion, significantly increased serum gastrin levels (p < 0.05).
• Sodium bicarbonate did not significantly alter gastrin levels, indicating the effect was specific to the antacid's components.
• Intravenous cimetidine effectively blocked the antacid-induced rise in gastrin, even at higher intragastric pH levels.

Conclusions:

• Antacid components, not acid neutralization alone, stimulate gastrin release in duodenal ulcer patients.
• Intravenous cimetidine prevents antacid-induced hypergastrinemia by reducing gastric acid secretion.
• This mechanism likely involves limiting the formation of ionic magnesium and aluminum.