Single-dose Pharmacokinetics of Garenoxacin in Healthy Korean Volunteers

건강한 한국인 자원자에서 Garenoxacin 단회투여에 의한 약동학적 특성 연구

Background: Garenoxacin is a des-F(6) quinolone antimicrobial drug with broad-spectrum activity. We investigated the safety and pharmacokinetic (PK) characteristics of garenoxacin after a single oral dose in healthy Korean male volunteers, and compared them to those of Japanese. Methods: A parallel, single ascending dose (200, 400 and 600 mg), dose-block randomized, double-blind, placebo-controlled study was conducted in 24 healthy Korean male volunteers. Subjects were randomized into each dose group (6 for active drug, 2 for placebo). For safety assessment, vital signs, laboratory tests, 12-lead electrocardiograms and adverse events were monitored. Plasma concentrations of garenoxacin were measured till 72 hours after drug administration. Concentration-time data was analyzed by noncompartmental methods and the results were compared to Japanese data from the previous study performed under the same protocol. Results: Regarding safety, all doses of garenoxacin were well tolerated without serious adverse events or clinically meaningful changes. The mean area under the concentration-time curve from 0 hour to the last measured concentration over the limit of quantitation ($C_{last}$) ($AUC_{last}$) were 43.9, 101.8, 155.7 mg*h/L and the maximum plasma concentration ($C_{max}$) were 4.7, 8.9, 13.6 mg/L in 200, 400 and 600 mg dose groups, respectively. The range of mean elimination half-life by dose groups was 12.3 to 12.4 h. Increases in systemic exposure to garenoxacin in terms of $AUC_{last}$ and $C_{max}$ were dose proportional over the dose range of 200 to 600 mg. The geometric mean ratios (90% confidence interval) for Koreans to Japanese were 0.97 (0.87-1.08) for dose-normalized $AUC_{last}$ and 1.08 (0.96-1.22) for dose-normalized $C_{max}$. Conclusion: Single oral doses of garenoxacin were well tolerated. Systemic exposures of garenoxacin were linear according to dose increments up to 600 mg dose. Comparison of the PK between Koreans and Japanese indicates that the pharmacokinetic characteristics were similar, which suggests that no dosage adjustment is required for garenoxacin in Koreans compared to Japanese.