In this open prospective study, the efficacy of pantoprazole in reducing gastric acid secretion in Zollinger-Ellison syndrome patients was compared to that obtained previously with other proton pump inhibitors.

Eleven male patients previously treated with omeprazole (n = 7, mean dosage: 63 mg/day; range: 20-100 mg/day) or lansoprazole (n = 4, mean dosage: 75 mg/day; range: 30-120 mg/day) were included. These patients underwent a 24-hour intragastric pH-metry, measurement of basal acid output and of serum gastrin first while receiving their usual therapy and second after 7 to 10 days of pantoprazole treatment at a mean dosage of 116 mg/day (range: 40-200 mg/day). Basal acid output was evaluated after each intragastric pH-metry, one hour before the next intake of proton pump inhibitor and a serum gastrin curve was determined according to 9 fixed time points.

One patient dropped out before the second intragastric pH-metry due to an adverse event (varicella) unrelated to pantoprazole and was reinvestigated thereafter. The median 24-h intragastric pH with pantoprazole was not significantly different than that with the other proton pump inhibitors (5.3 versus 4.6, respectively; P = 0.90). Neither the median basal acid output values nor the median serum gastrin levels were significantly different between pantoprazole and the other proton pump inhibitors.

In these patients with the Zollinger-Ellison syndrome, pantoprazole was well tolerated and equally effective to the other proton pump inhibitors in terms of antisecretory potency.