Pharmacokinetics and safety of sitafloxacin after single oral doses in healthy volunteers

OBJECTIVE Sitafloxacin is a new fluoroquinolone with a broad spectrum of antibacterial activity, including grampositive and gram-negative bacteria. This study was to evaluate the pharmacokinetic characteristics of a single dose of sitafloxacin in healthy Chinese volunteers. METHODS This was a single-center, open-label, randomized-sequence study conducted in 12 subjects. Subjects were randomly assigned to receive single doses of 50, 100, and 200 mg of sitafloxacin in a 3-way crossover design with a 7-day washout period between administrations. Quantification was carried out using a validated high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method. Pharmacokinetic parameters were calculated and analyzed statistically. Safety assessments were conducted throughout the study. RESULTS After administration of single doses of 50, 100, and 200 mg, geometric mean estimate for sitafloxacin Cmax were 0.72, 1.62, and 2.73 μg/mL and the mean of AUClast were 3.97, 8.71, and 18.03 μg x h/mL, respectively. Sitafloxacin was rapidly absorbed, reaching Cmax ranged from 0.85 to 1.21 hours. The terminal half-life ranged from 5.19 to 6.28 hours. The Cmax and AUC last were proportional to the doses. The mean clearance, the half-life, and the volume of distribution were constant, irrespective of the dose. CONCLUSION In healthy Chinese subjects, single dosing of sitafloxacin resulted in linear plasma pharmacokinetics.