Abstract: AIM: To carry out PK/PD study of gemifloxacin mesylate against common pathogenic bacteria in urinary tract.METHODS: MIC (minimum inhibitory concentration) and MBC (minimum bactericidal concentration) of gemifloxacin against common pathogenic bacteria in urinary tract were determined. Urine concentration of healthy subjects after oral administration of gemifloxacin mesylate tablets (320 mg) was determined and then C_max/MIC₉₀ and AUC_{24 h}/MIC₉₀ were calculated.RESULTS: Gemifloxacin had lower sensitivity to common pathogenic bacteria in urinary tract. Urinary peak concentration (C_max) of gemifloxacin was(144±124) μg/mL and the area under urine concentration-time curve (AUC_{24 h}) was(1368±671) μg·mL^-1·h after orally administered gemifloxacin mesylate tablets (320 mg) to healthy subjects. C_max/MIC₉₀ of gemifloxacin in urine against Escherichia coli, Pseudomonas aeruginosa and Enterococcus faecalis was 2.9-5.8 and AUC_{24 h}/MIC₉₀ was more than 30, whereas AUC_{24 h}/MIC₉₀ of gemifloxacin against Klebsiella pneumoniae and Enrerococcus feces was 19.25.CONCLUSION: Gemifloxacin could effectively remove Escherichia coli, Pseudomonas aeruginosa and Enterococcus faecalis infected in urinary tract, and avoid resistance. Gemifloxacin could inhibit growth of Klebsiella pneumoniae and Enterococcus feces.

Key words: gemifloxacin mesylate, MIC, MBC, PK, PD