Helicobacter pylori infection influences nocturnal gastric acid breakthrough

Nocturnal gastric acid breakthrough is defined as night-time periods when gastrin pH falls below 4.0 for greater than 1h during administration of a proton pump inhibitor. This phenomenon is a serious problem for patients who require strict control of their gastric acid secretions.

To investigate the prevalence of nocturnal gastric acid breakthrough in Japanese subjects during administration of rabeprazole, and to clarify the relationship between Helicobacter pylori infection and nocturnal gastric acid breakthrough.

Thirty-one normal male volunteers were examined by ambulatory 24 h gastric pH monitoring four times: without medication, after a morning or an evening dose of 20 mg rabeprazole, and after administration of an H2-receptor antagonist at bedtime, in addition to the morning dose of rabeprazole. H. pylori infection was determined by the 13C-urea breath test and an assay for serum anti-H. pylori antibody.

Nocturnal gastric acid breakthrough was observed in 12 patients (39%) after the morning dose of 20 mg rabeprazole. In all cases, nocturnal gastric acid breakthrough was inhibited completely by administration of the H2-receptor antagonist at bedtime. Only one patient with nocturnal gastric acid breakthrough had H. pylori infection.

The absence of H. pylori infection appears to be closely related to the occurrence of nocturnal gastric acid breakthrough during dosing with a proton pump inhibitor.