title: Pharmacokinetics of intravenously administered levofloxacin in men and women.
abstract: OBJECTIVE
  To characterize and compare the pharmacokinetics of levofloxacin in men and women after systemic administration.
  
  
  METHODS
  Prospective, open-label, parallel group pharmacokinetic study.
  
  
  METHODS
  University research center.
  
  
  METHODS
  Eleven healthy men and nine healthy women stratified by body mass index.
  
  
  METHODS
  Subjects received levofloxacin as a single 500-mg intravenous dose. Serum and urine were collected over 36 hours.
  
  
  RESULTS
  Levofloxacin concentrations were determined by high-performance liquid chromatography with ultraviolet detection. Pharmacokinetic analysis was performed with ADAPT II software (University of Southern California, Los Angeles, CA). Median (range) body mass index was 23.2 kg/m2 (19.9-28.3 kg/m2) for men and 23.6 kg/m2 (16.0-32.4 kg/m2) for women (p = 0.67). A two-compartment model best fit the pharmacokinetic data: median (range) R2 was 0.996 (0.990-0.999). Women had a 24% greater exposure to levofloxacin, with a significantly smaller steady-state volume of distribution (p < 0.01) and a slower clearance (p < 0.01).
  
  
  CONCLUSIONS
  Differences exist in the disposition of levofloxacin between healthy men and women after systemic administration. Fixed intravenous doses of levofloxacin will lead to greater drug exposure in women. Thus, women may have more of an increased risk of fluoroquinolone toxicity than men, and men may need higher doses to achieve similar drug efficacy than women. Levofloxacin dosage adjustments based on sex should be considered on an individual basis.
authors.affiliation: Department of Pharmacy Practice, Purdue University School of Pharmacy and Pharmaceutical Sciences, Indianapolis and West Lafayette, Indiana 46202, USA.
authors.forename: Brian R
authors.initials: BR
authors.lastname: Overholser
authors.forename: Michael B
authors.initials: MB
authors.lastname: Kays
authors.forename: Seema
authors.initials: S
authors.lastname: Lagvankar
authors.forename: Mitchell
authors.initials: M
authors.lastname: Goldman
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Mueller
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Sowinski
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000493:pharmacokinetics*; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D064704:Levofloxacin; D008297:Male; D008657:Metabolic Clearance Rate; D015242:Ofloxacin / Q000008:administration & dosage / Q000009:adverse effects / Q000493:pharmacokinetics*; D011446:Prospective Studies; D012044:Regression Analysis; D012727:Sex Characteristics
chemical_list: D000900:Anti-Bacterial Agents; D064704:Levofloxacin; D015242:Ofloxacin