Effects of omeprazole on acid secretion and acid-related symptoms in patients with Zollinger-Ellison syndrome.

In the Zollinger-Ellison syndrome, symptoms and complications are due to hypersecretion of acid, and the first therapeutic step is to suppress the acid secretion. Long-term treatment with histamine H2-receptor antagonists was compared with omeprazole treatment. A total of 30 consecutive ZES patients were treated continuously with H2-receptor antagonists. During long-term treatment, a marked tachyphylaxis was noted, more than 50% of the patients had periods of dyspepsia, recurrent ulcers were found in 10 patients and in 16 a decline in the action of the H2-receptor antagonist required a change to omeprazole after a median duration of 36 months. A total of 22 patients were treated with omeprazole. During long-term treatment, the dose could be reduced slightly. Inhibition of acid secretion was maintained in all cases, and none had dyspeptic symptoms. The median duration of treatment was 18 months, with a range of 1-120 months (H2-receptor antagonists) and 27 months with a range of 1-66 months (omeprazole). No side-effects were seen with omeprazole.