Effect of carbenoxolone on gastric prostaglandin E2 levels in patients with peptic ulcer disease following vagal and pentagastrin stimulation

The influence of oral carbenoxolone sodium (50 mg X 3 daily) on prostaglandin E2 release into gastric juice has been examined in nine peptic ulcer patients (duodenal ulcer, n = 6; prepyloric ulcer, n = 1; gastric ulcer, n = 2) during modified sham feeding and following bolus stimulation of acid secretion by pentagastrin (6 micrograms/kg). Carbenoxolone increased the overall mean of prostaglandin E2 concentrations in gastric juice following modified sham feeding by 32 +/- 9% (mean +/- SEM; P less than 0.02) and decreased the acidity slightly but significantly (P less than 0.05). A marked rise in prostaglandin E2 levels (46 +/- 11%; n = 5; P less than 0.02) was observed in for duodenal ulcer patients and the patient with a prepyloric ulcer responding to therapy (i.e., pain relief and ulcer healing within 4 weeks of treatment). A significant peak (P less than 0.05) related to modified sham feeding was observed only during medication, while a late gradual increase in prostaglandin E2 levels--not associated with vagal stimulation--occurred both in control and carbenoxolone experiments. No significant differences were observed following pentagastrin stimulation. The initial peak in prostaglandin E2 levels observed during medication favours the notion that the mechanism of drug action relies on inhibition of enzymatic degradation while the late increase in prostaglandin E2 levels may be explained by artificial prostaglandin formation during the aspiration procedure.