THE COMPARATIVE EFFECTS OF SINGLE INTRAVENOUS DOSES OF CIMETIDINE, RANITIDINE, FAMOTIDINE, AND OMEPRAZOLE ON INTRAGASTRIC PH

Twelve healthy subjects participated in this randomized, double-masked , four-way crossover study to determine treatment schedules for intrav enous (IV) administration of various gastric antisecretory drugs, Intr agastric pH was monitored continuously for 14 hours after a single IV injection of cimetidine 300 mg, ranitidine 50 mg, famotidine 20 mg, or omeprazole 40 mg, each administered during one of four successive tre atment periods separated by B-day washout periods, The primary efficac y variable, the length of time that intragastric pH remained >3.5, was significantly longer after famotidine treatment (516 +/- 143 minutes) than after treatment with cimetidine (355 +/- 239 minutes), ranitidin e (285 +/- 235 minutes), or omeprazole (270 +/- 253 minutes), Conseque ntly, the duration of the antisecretory effect (the length of time nee ded for the pH to return to the baseline level) was also significantly longer after famotidine treatment (635 +/- 131 minutes) than after ci metidine (451 +/- 259 minutes), ranitidine (414 +/- 205 minutes), or o meprazole (393 +/- 259 minutes), On the basis of the area under the ga stric pH profile curve over 14 hours, famotidine was again shown to be a significantly more effective antisecretory agent than the other thr ee drugs, There were no significant differences between the four agent s for maximum pH level achieved, length of time to reach the maximum p H level after drug administration, and length of time between drug adm inistration and the first occurrence of a pH level >3.5, No adverse ev ents were recorded during the study.