title: Gatifloxacin pharmacokinetics in healthy men and women.
abstract: The sex-based pharmacokinetics of gatifloxacin were investigated. Healthy subjects (6 men, 6 women) received a single oral dose of gatifloxacin 400 mg. Blood and urine samples were collected, and gatifloxacin concentrations were determined by high-performance liquid chromatography. Pharmacokinetic parameters were estimated by fitting appropriate models to the serum concentration-time data using ADAPT II. Linear regression analysis was used to determine the influence of sex and weight on the oral clearance (CL(s)/F) and apparent steady-state volume of distribution (V(ss)/F) of gatifloxacin. Women had a significantly smaller V(ss)/F compared to men (93.5 +/- 21.3 L vs 128.8 +/- 16.2 L, P = .009); however, there was no significant difference when normalized for total body weight (TBW) or lean body weight (LBW). Neither CL(s)/F nor peak serum concentration (C(max)) was significantly different between sexes, although C(max) was 25% higher in women (P = .06). Regression analyses revealed that TBW (R(2) = .63) and LBW (R(2) = .65) were strong predictors of V(ss)/F. Given the smaller V(ss)/F, women may have slightly higher maximum concentrations, but these differences are unlikely to have clinical significance.
authors.affiliation: Department of Pharmacy Practice, School of Pharmacy and Pharmaceutical Sciences, Purdue University, Indianapolis, Indiana 46202, USA.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.forename: Brian R
authors.initials: BR
authors.lastname: Overholser
authors.forename: Michael B
authors.initials: MB
authors.lastname: Kays
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Sowinski
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000890:Anti-Infective Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*; D019540:Area Under Curve; D001835:Body Weight / Q000502:physiology; D002851:Chromatography, High Pressure Liquid; D005260:Female; D024841:Fluoroquinolones / Q000097:blood / Q000493:pharmacokinetics* / Q000652:urine; D000077734:Gatifloxacin; D006207:Half-Life; D006801:Humans; D016014:Linear Models; D008297:Male; D008657:Metabolic Clearance Rate; D012737:Sex Factors
chemical_list: D000890:Anti-Infective Agents; D024841:Fluoroquinolones; D000077734:Gatifloxacin