Abstract
The in vitro and in vivo antimicrobial effects of a new quinolone antimicrobial drug, grepafloxacin (GPFX), were examined and compared with those of ofloxacin (OFLX), enoxacin (ENX), ciprofloxacin (CPFX) and tosufloxacin (TFLX) with the following results.
GPFX had a wide antimicrobial spectrum and the antimicrobial activities against Staphylococcus, including methicillin-resistant Staphylococcus aureus (MRSA), Enterococcus and Streptococcus, were almost equal to those of TFLX. The antimicrobial effects of GPFX against various strains of intestinal flora were slightly weaker than those of CPFX and TFLX but were strongest against gram-negative bacteria including Haemophilus influenzae and Neisseria gonorrhoeae.
The therapeutic effect of GPFX in a mouse systemic infection model was slightly inferior to that of TFLX against S. aureus Smith, S. aureus TMS 33 and Streptococcus pneumoniae, but superior to the control drugs against Escherichia coli C-11, Klebsiella pneumoniae 3K25 and Pseudomonas aeruginosa. In a transnasal pulmonary infection model using K. pneumoniae 3K25, S. pneumoniae TMS 3 and S. aureus Smith as infective strains, the therapeutic effect of GPFX was superior to that of TFLX. In a urinary infection model (P. aeruginosa KU-1), the therapeutic effect of GPLX was equal to that of CPFX.
When the concentrations of GPFX in mouse serum, lung and kidney were examined, the drug was found to be distributed at higher levels in the lung and kidney, although the serum concentration was lower than when other drugs were used.
