The effect of food on the pharmacokinetics of ofloxacin

Abstract

After oral administration of a single dose of ofloxacin (300 mg), with and without a standard breakfast, to 12 healthy male volunteers in an open, randomized crossover study, concentrations of the unchanged drug were estimated at various times in serum and urine, over 28 hours and 48 hours, respectively. Each dose was followed by a wash-out period of 1 week. Ofloxacin concentrations were determined using high pressure liquid chromatography (HPLC): parallel determinations using a microbiological assay were in close agreement. Maximum serum concentrations (Cmax) of ofloxacin, after fasting and with breakfast, respectively, were 3.7 and 3.1 micrograms/ml (HPLC, median values). The corresponding areas under the serum concentration-time curves (AUC0-28) were 29.9 and 24.5 micrograms/ml. The lower values of Cmax and AUC0-28 found after food intake were statistically significant (p less than 0.05) but not clinically relevant when compared to the fasting values. Time to reach Cmax and terminal elimination half-life (t1/2 beta) were not significantly affected by food intake: t1/2 beta was calculated as 5.3 and 5.9 hours (HPLC, median values), fasting and with breakfast, respectively. Urinary recovery (after 48 hours: 72% and 74%, respectively) was also not significantly affected by food intake, and urinary concentrations of ofloxacin remained far above 1 microgram/ml, i.e. above the minimum inhibitory concentration (MIC90) for most bacterial strains, for at least 48 hours after drug administration. General tolerability was good; no side-effects were reported.