Inhibition of pentagastrin-induced gastric acid secretion by intravenous pantoprazole: a dose-response study

The purpose of this study was to compare the gastric acid inhibitory ability of increasing doses of intravenous (i.i.) pantoprazole with that of i.v. famotidine and placebo. Pentagastrin was infused continuously in healthy subjects as a model for patients with Zollinger-Ellison syndrome.

Pentagastrin (1 microg/kg/h) was infused to stimulate maximum acid output in 39 subjects over a 25-h period. After 60 min of pentagastrin infusion, subjects received a single dose of i.v. pantoprazole (20, 40, 80, or 120 mg), i.v. famotidine (20 mg), or saline placebo. The variables measured were onset of response (time until acid output fell to < 10 mEq/h), duration of response (time acid output remained < 10 mEq/h), and cumulative acid output over 24 h.

All doses of i.v. pantoprazole produced a dose-dependent suppression of acid output to < 10 mEq/h. Single i.v. doses of pantoprazole, 80 and 120 mg, suppressed acid output by > 90% in all subjects for < or = 21 h and had an onset of action of < 1 h.

Intravenous pantoprazole has a rapid onset and a clear dose-related effect, with a significantly longer duration of action than that of i.v. famotidine.