Omeprazole in the Zollinger-Ellison syndrome.

Treatment with omeprazole was evaluated in nine patients with the Zollinger-Ellison syndrome, in whom the effect of H2-receptor antagonists had become inadequate. Treatment with 20-80 mg omeprazole daily reduced basal acid secretion by 77-100%. The effect persisted during a continuous treatment of up to 2 years. In five patients the initial dose could be reduced after some time of treatment. In eight patients the treatment promptly relieved all symptoms, and in the last patient, who had disseminated metastatic disease and large anastomotic ulcers, the symptoms disappeared gradually over a period of 10 weeks. No adverse events were seen. We conclude that omeprazole is an effective inhibitor of the acid hypersecretion in Zollinger-Ellison patients, also when H2-receptor antagonists have failed.