Effect of food and gastric pH on the bioavailability of grepafloxacin.

Two open crossover studies were conducted to investigate the effects of food or concomitant treatment with the histamine H2-receptor antagonist famotidine on the pharmacokinetics of the new fluoroquinolone grepafloxacin. Each study involved 16 healthy male volunteers. In the first study, participants received grepafloxacin 600 mg, either after fasting or after consumption of a standard high-fat meal. There were no significant differences in any pharmacokinetic parameter under the fasting or nonfasting conditions. In the second study, participants received grepafloxacin 400 mg, either alone or after infusion of famotidine 20 mg; additional doses of famotidine were given, if necessary, to maintain intragastric pH above 6. Famotidine treatment had no significant effect on grepafloxacin pharmacokinetics. The results of these studies indicate that neither food nor the elevation of gastric pH influence the absorption or bioavailability of grepafloxacin. Therefore, grepafloxacin can be administered with or without food.