Dual effects of rabeprazole on solid-phase gastric emptying assessed by the 13C-octanoate breath test

Knowledge is limited regarding the effects of rabeprazole on gastric emptying. This randomized, open, crossover study was undertaken to investigate the effects.

In 24 healthy volunteers (13 men and 11 women, aged 22-53 years), solid emptying was assessed twice using the 13C-octanoate breath test. On one occasion, the subjects received 20 mg rabeprazole for the preceding 2 days and 1 h before the test. On another occasion, they underwent no pretreatment. The time course of cumulative recovery of 13CO2 in breath was fitted to z(t)=m(1-e-kt)beta-1, and regression constants of k and beta were determined. The half 13CO2 excretion time (t(1/2)b)) and the time of maximal excretion (tmax) were calculated. Under the crossover protocol, k and beta can describe the emptying features more precisely; a larger (smaller) beta indicates a slower (faster) emptying in the early phase, and a larger (smaller) k indicates a faster (slower) emptying in the later phase. Between the two occasions, k, beta, t(1/2)b, and tmax were compared.

Rabeprazole significantly decreased k and beta, significantly prolonged t(1/2)b, but tmax remained unchanged.

Rabeprazole has dual effects on solid emptying: an initial acceleration with a subsequent deceleration, resulting in an overall delay.