A placebo-controlled study to assess the effects of 7-day dosing with 10, 20 and 40 mg rabeprazole on 24-h intragastric acidity and plasma gastrin in healthy male subjects.
OBJECTIVE
To compare the effects of rabeprazole 10, 20 and 40 mg o.d. on 24-h intragastric acidity and plasma gastrin concentration in a randomized, double-blind placebo-controlled trial.


METHODS
Twenty-four healthy male volunteers were studied on the 7th day of morning dosing with either placebo or rabeprazole 10, 20 or 40 mg in a crossover fashion. On day 7, hourly intragastric acidity was measured for 24 h from 08.00 hours by gastric aspiration. Plasma gastrin concentrations were also measured hourly from 08.00 to 24.00 hours, and 2-hourly thereafter.


RESULTS
Compared with placebo, rabeprazole 10, 20 and 40 mg produced significant dose-related decreases in intragastric acidity (median 24-h integrated acidity=697, 186, 129 and 82 mmol h/L, respectively). This was associated with significant elevation of plasma gastrin concentration (median 24-h integrated gastrin=141, 1184, 1484 and 1763 pmol.h/L, respectively). Rabeprazole 40 mg resulted in significantly decreased acidity compared with both 10 and 20 mg, and in longer times for which intragastric pH was maintained at > 3 (19. 2 h vs. 17.3 h and 17.5 h) and > 4 (17 h vs. 14.2 h and 15.2 h), but was accompanied by significantly increased plasma gastrin. There was a consistent trend for greater antisecretory activity for 20 mg compared with 10 mg, but these differences did not reach statistical significance. The interindividual variability in antisecretory response was greatest with 10 mg.


CONCLUSIONS
Rabeprazole 10, 20 and 40 mg produce significant, profound dose-related inhibition of gastric acid secretion. Taking into account reciprocal increases in plasma gastrin and the interindividual variation in antisecretory response, 20 mg appears to be the preferred dose for routine clinical use.
Williams
M P
MP
Centre for Gastroenterology, Royal Free and University College Medical School, London, UK.
Blanshard
C
C
Millson
C
C
Sercombe
J
J
Pounder
R E
RE
D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000328:Adult; D000897:Anti-Ulcer Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D001562:Benzimidazoles / Q000008:administration & dosage* / Q000627:therapeutic use; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005744:Gastric Acid / Q000378:metabolism*; D005745:Gastric Acidity Determination; D005755:Gastrins / Q000097:blood / Q000187:drug effects; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D009853:Omeprazole / Q000031:analogs & derivatives; D064750:Rabeprazole; D013276:Stomach Ulcer / Q000188:drug therapy; D016896:Treatment Outcome
D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000897:Anti-Ulcer Agents; D001562:Benzimidazoles; D005755:Gastrins; D064750:Rabeprazole; D009853:Omeprazole