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

Summary 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 ≥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 ≤ esomeprazole 20 mg < rabeprazole 20 mg = esomeprazole 40 mg. Esomeprazole acts faster, whereas rabeprazole's effect lasts longer.