Addition of misoprostol to ranitidine in non-responders to H2-blockers and pirenzepine.

In the present study, which comprised 14 patients in whom 300 mg and 900 mg of ranitidine as well as in combination with pirenzepine had failed to suppress acid secretion, we tested the effect of adding misoprostol. Night-time intragastric pH was continuously monitored, a rise in the intragastric pH above 4.0 h more than 6 h following the oral dose at 18.00 h being considered a response. In only 1 of the 7 patients with cirrhosis, and in 1 of the 7 control patients, did the combination of 300 mg ranitidine and 400 micrograms of misoprostol result in sufficient acid suppression. Mean pH profiles during the four study periods were not significantly different and the effect of misoprostol was similar in cirrhotics and controls. The inefficacy of the addition of misoprostol in this selected group of patients who did not respond even high doses of ranitidine (+/- pirenzepine) does not favour the hypothesis that gastric mucosal prostaglandin efficiency may be an important factor in the non-response to H2-receptor antagonists. It appears unlikely that the cause is localized solely at the site of H2-receptors.