Control of nocturnal gastric acidity: a role for low dose bedtime ranitidine to supplement daily omeprazole.

In some patients, proton pump inhibitors do not abolish nocturnal gastric acidity and additional evening antisecretory medication may be required. In 16 subjects with chronic heartburn, 24-hr gastric and esophageal pH were measured at baseline and again after six days of 20 mg omeprazole alone at 08:00 hr followed by placebo, 75 mg ranitidine, or 20 mg omeprazole at 22:00 hr. Integrated acidity was calculated from the cumulative, time-weighted mean acid concentrations (derived from pH values for each second). Baseline integrated gastric acidity increased progressively over 24 hr, whereas integrated esophageal acidity increased only until 22:00 hr. Morning omeprazole nearly abolished 24-hr esophageal acidity and significantly decreased overall gastric acidity but did not abolish nocturnal gastric acidity. Adding evening ranitidine or omeprazole nearly eliminated the nocturnal increase in gastric acidity. Integrated acidity was more sensitive than time pH < 4 in assessing gastric and esophageal acidity as well as their inhibition by omeprazole and ranitidine. In conclusion, integrated acidity provides novel information regarding the synergy of omeprazole plus ranitidine. Adding low-dose ranitidine helps control nocturnal gastric acidity that can occur with conventional omeprazole administration. Although the heartburn patients in the present study had nocturnal gastric acidity without accompanying nocturnal esophageal acid reflux, other patients who do have nocturnal esophageal reflux might profit from addition of bedtime ranitidine or another gastric antisecretory agent.