Evaluation of antisecretory drug therapy of Zollinger-Ellison syndrome (ZES) using 24-hour pH monitoring.

Clinical and endoscopic findings were compared with 24-hr pH profiles in 8 patients with Zollinger-Ellison syndrome (ZES), who were being treated, during consecutive periods, with doses of cimetidine or ranitidine. There was a positive correlation between the effect on gastric pH and the outcome of treatment, with ranitidine proving to be more effective. The reduction of gastric acidity was correlated with ranitidine plasma levels. In the medical management of ZES patients, the 24-hr pH profile appears to be a measurement which is of value in the choice of appropriate drug regimes and which promises to increase our understanding of treatment failure.