Combined analysis of three crossover clinical pharmacology studies of effects of rabeprazole and esomeprazole on 24‐h intragastric pH in healthy volunteers

AIM: To compare antisecretory effects of rabeprazole and esomeprazole after single and repeat dosing in Helicobacter pylori-negative healthy volunteers. METHODS: Results were pooled from three smaller, open, crossover, randomized studies to obtain data from 80 subjects. The studies compared: (a) 5 days' dosing of 20 mg rabeprazole and esomeprazole (n = 24); (b) single doses of rabeprazole 20 mg and esomeprazole 40 mg (n = 27) and (c) 5 days' dosing of rabeprazole 10 mg and esomeprazole 20 mg (n = 29). Washout periods were > or =14 days. Intragastric pH was recorded continuously for 24 h on days 0, 1 and 5. RESULTS: Single doses of rabeprazole 20 mg maintained 24-h intragastric pH >4 for longer than esomeprazole 20 mg (45% vs. 32%; P < 0.001); rabeprazole 20 mg and esomeprazole 40 mg were equivalent in their effects. After 5 days' dosing, rabeprazole 20 mg maintained pH >4 for longer than esomeprazole 20 mg (62% vs. 56%; P = 0.046); the reverse was true for esomeprazole 20 mg vs. rabeprazole 10 mg (56% vs. 48%; P = 0.035). In general, intragastric pH AUC during 0-5 h after dosing was higher after esomeprazole than rabeprazole, whereas the reverse was true during the night. CONCLUSIONS: The order of effects on 24-h pH was: rabeprazole 10 mg < or = esomeprazole 20 mg < rabeprazole 20 mg = esomeprazole 40 mg. Esomeprazole acts faster, whereas rabeprazole's effect lasts longer.