Four‐day continuous gastric pH monitoring following anti‐acid secretory drug administration: cross‐over test to assess the early effects

BACKGROUND: There have been few reports that compare the effect of histamine H2-receptor antagonists (H2RAs) and proton pump inhibitors (PPIs) using continuous gastric pH monitoring for a long duration. AIM: To assess the early effects of both drugs on gastric pH using a wireless pH monitoring system. METHODS: The test was conducted by a cross-over test: 10 healthy male volunteers were administered famotidine 20 mg twice a day and lansoprazole 30 mg once a day. Monitoring of gastric pH over four consecutive days was performed using a unique method we have developed that is an elaboration of the Bravo system. RESULTS: The time to reach a pH level of 3 or more with famotidine was significantly shorter than that for lansoprazole. The pH3 holding time ratio of famotidine during the first 4 h of administration was significantly higher than that of lansoprazole. The pH3 holding time ratio on each day from day 1 to day 3 was significantly higher following lansoprazole administration compared with famotidine administration. CONCLUSIONS: Famotidine was shown to act quickly in elevating gastric pH; however, lansoprazole was superior to famotidine in terms of its ability to elevate gastric pH for a long duration.