Use of omeprazole in Zollinger-Ellison syndrome: a prospective nine-year study of efficacy and safety.

Abstract

H+, K(+)-ATPase inhibitors such as omeprazole are the antisecretory agents of choice for the management of gastric acid hypersecretory states, including the Zollinger-Ellison syndrome. However, long-term follow-up data on the overall efficacy and safety of these agents in large numbers of patients are lacking. In the current study we examined the long-term efficacy and safety of omeprazole in 116 patients with Zollinger-Ellison syndrome treated with oral omeprazole at a single centre for up to 114 months (mean +/- S.E.M. = 38 +/- 3 months). The initial omeprazole maintenance dose was established according to the acute upward dose titration method in 89/116 patients (77%). Gastric acid output was effectively controlled using 60 mg of omeprazole once daily in 41/89 patients (46%) and 22/89 patients (25%) required twice daily omeprazole therapy. The mean ranitidine equivalent dose for patients who required 60 mg omeprazole once daily (2.5 +/- 0.2 g/day) was significantly lower than the mean ranitidine equivalent dose for patients who required more than 60 mg omeprazole once daily (4.3 +/- 0.3 g/day). Long-term omeprazole maintenance therapy was discontinued in 36/116 patients (31%) but in no cases was discontinuation due either to drug-induced side-effects or uncontrolled gastric acid output. Fasting serum gastrin levels were significantly elevated above pre-treatment levels at only one time point during follow-up and were likely due to tumour growth rather than a drug effect. The final long-term omeprazole maintenance doses were lower than the initial doses but correlated closely with the pre-omeprazole basal acid output (r = 0.41, P < 0.001) and ranitidine equivalent dose requirements (r = 0.49, P < 0.001). We conclude that omeprazole effectively and safely controls gastric acid hypersecretion in all patients with Zollinger-Ellison syndrome for up to nine years without evidence by tachyphylaxis.

• Authors: D C Metz, D B Strader, M Orbuch, P D Koviack, K M Feigenbaum, R T Jensen
• Journal: Alimentary pharmacology & therapeutics (Aliment Pharmacol Ther) Vol. 7 Issue 6 Pg. 597-610 (Dec 1993) ISSN: 0269-2813 [Print] England
• PMID: 8161665 (Publication Type: Clinical Trial, Comparative Study, Journal Article)

Chemical References

• Gastrins
• Ranitidine
• Omeprazole

Topics

• Administration, Oral
• Adolescent
• Adult
• Aged
• Dose-Response Relationship, Drug
• Female
• Follow-Up Studies
• Gastric Acid (metabolism)
• Gastrins (blood)
• Humans
• Male
• Middle Aged
• Omeprazole (administration & dosage, adverse effects, pharmacology, therapeutic use)
• Prospective Studies
• Ranitidine (administration & dosage, therapeutic use)
• Zollinger-Ellison Syndrome (drug therapy)