Pharmacokinetic study of levofloxacin in Chinese healthy volunteers

OBJECIIVE: To study the pharmacokinetics of single oral administration and intravenous infusion of levofloxacin in Chinese healthy volunteers. METHODS: Intravenous infusion of levofloxacin 200 mg within 60 rain, or the same dose of levofloxacin tablet orally was given to 18 male healthy volunteers in randomized self-control crossover study. To another 18 healthy subjects, infusion of levofloxacin 300 mg was given intravenously within 60 min and 90 min, respectively. The concentrations of levofloxacin in serum and urine were assayed by HPLC. RESULTS: The mean pharmacokinetic parameters of 200 mg levofloxacin injection and tablet were cmax (3.06 ± 0.32) mg&middotL-1 and (2.50 ± 0.39) mg&middotL-1, AUC (17.79 ± 1.62) mg&middoth&middotL-1 and (17.02 ± 1.79) mg&middoth&middot L-1, t1/2β (5.60 ± 0.31) h and (5.73 ± 0.48) h, respectively. The 48 hour cumulative urinary excretion rates were (72.58 ± 8.66)% and (71.50 ± 6.75)% respectively. The absolutely bioavailibility was (96.03 ± 9.35)%. In 300 mg group, the main pharmacokinetic parameters of infusion 60 min and 90 min were as follows: cmax (4.63 ± 0.59) mg&middotL-1 and (4.21 ± 0.66) mg&middotL-1, AUC (29.17 ± 2.66) mg&middoth&middotL-1 and (29.04 ± 3.76) mg&middoth&middotL-1, t1/2β(6.05 ± 0.30) h and (5.96 ± 0.48) h, respectively. The 48 h cumulative urinary excretion rates were (74.50 ± 9.32)% and (77.68 ± 8.86)% respectively. The main pharmacokinetic parameters showed no significant difference except the cmax. No adverse events were noted in any of the above studies. CONCLUSION: It suggested that there were the same pharmacokinetic behavior in 200 mg and 300 mg dose groups. The absolutely bioavailibility of levofloxacin tablet was (96.03 ± 9.35)%.