Effect of gender on the pharmacokinetics of ofloxacin.

STUDY OBJECTIVES

To assess the influence of gender on the pharmacokinetics of ofloxacin.

DESIGN

Open-label study.

SETTING

Academic medical center.

PATIENTS

Five healthy men and seven healthy women volunteers.

INTERVENTIONS

Subjects received a single oral dose of ofloxacin 400 mg, and serial blood samples were collected for 24 hours. Plasma concentrations of ofloxacin were determined by high-performance liquid chromatography and pharmacokinetic parameters were determined. Statistical comparisons between genders were made with the Wilcoxon rank sum test.

MEASUREMENTS AND MAIN RESULTS

Median volume of distribution at steady state/systemic bioavailability (V(ss)/F) was significantly smaller in women than in men, although when normalized for total body weight there were no differences. Except for terminal elimination half-life, which was 10% shorter in women, no other pharmacokinetic values were significantly different between genders. Median peak concentrations, although not statistically different, were 28% higher in women.

CONCLUSION

Ofloxacin V(ss)/F values were smaller in women than in men, explained by gender-related differences in weight.