Aim: To compare antisecretory effects of Rabeprazole and Esomeprazole in proton pump inhibitors extensive metabolizers in an open, randomized, two-way crossover study.
Methods: Sixteen GERD H. pylori-positive patients (8 men, mean age 49.6 and 8 women, mean age 49.3) with the homozygous extensive metabolizer genotype of CYP2C19 determined by polymerase chain reaction-restriction fragment length polymorphism analysis received Rabeprazole 20 mg or Esomeprazole 20 mg daily on days 1-6, with a 14-day wash-out period. Intragastric pH was recorded continuously on days 0, 1, 5 and 7.
Results: On days 1 and 5 no differences were found between Rabeprazole 20 mg and Esomeprazole 20 mg in 24-hours median pH (day 1: 5.9 versus 5.0; day 5: 6.45 versus 6.3) or in percent of time with pH 4 (day 1: 57.8% versus 50.5%; day 5: 81.4% versus 81.2%). On day 1, mean percent of time pH 4 were significantly greater after Esomeprazole 20 mg 52.6% (95% CI: 23.6-68.2) than Rabeprazole 20 mg 33.0% (95% CI: 15.3-48.2) during 0-6 h (p = 0.02). On day 7 (24 later the last dose), 24-hours median pH was higher after Esomeprazole 20 mg than Rabeprazole 20 mg (2.7 versus 5.05; p = 0.02).
Conclusions: Rabeprazole 20 mg and Esomeprazole 20 mg are equally effective in increasing gastric pH in H. pylori-positive PPI extensive metabolizers on days 1 and 5. Esomeprazole 20 mg is more effective than Rabeprazole 20 mg in maintaining pH 4 during the first 6 hours on the first day and increasing of intragastric pH on the day 24 hours later the last dose.