Evaluation of the effect of lansoprazole in suppressing acid secretion using 24-hour intragastric pH monitoring.

The acid-inhibitory effect of lansoprazole was evaluated in comparison with that of famotidine and omeprazole by using 24-h intragastric pH monitoring in 10 young, healthy Japanese volunteers. Lansoprazole 20 mg once daily in the morning was superior to famotidine 20 mg twice daily, omeprazole 20 mg once daily in the morning in reducing 24-h intragastric acidity. Unlike famotidine, whose acid-inhibitory effect was observed mainly at night, both lansoprazole and omeprazole inhibited both daytime and nocturnal acid secretion, with the maximal effect occurring in the afternoon. Although the daily profile of acid-inhibitory action of lansoprazole was similar to that of omeprazole, the acid-inhibitory effect of lansoprazole was more potent than that of omeprazole at any time of the day. These results indicate that lansoprazole at a dosage of 30 mg once daily in the morning produced the most potent inhibition of acid secretion in young Japanese volunteers, compared with famotidine 20 mg twice daily and omeprazole 20 mg once in the morning.