Bacteriological and clinical studies on NM441

The in vitro activity of NM394, an active form of the newly developed quinolone NM441, for oral use, was studied by determining minimum inhibitory concentration (MIC) by an agar two-fold dilution method. The MICs of NM394 ranged from 0.78 to more than 100μg/ml against 16 strains of Staphylococcus aureus with the mecA gene, but showed excellent activity against 10 strains without the mecA gene and against which the MICs of NM394 ranged from 0.2 to 0.78μg/ml. NM394 was more active than ofloxacin (OFLX) and fleroxacin (FLRX) and almost equally active to ciprofloxacin (CPFX) against S. aureus without the mecA gene. NM394 was more active than OFLX, CPFX and FLRX against Escherichia coli and Klebsiella pneumoniae. The MICs of NM394 ranged from 0.025 or less to 0.1μg/ml against E. coli, from 0.025 or less to 3.13μg/ml against K. pneumoniae, and 0.1 to 25μg/ml against Pseudomonas aeruginosa. NM394 was more active than OFLX and FLRX and almost equally active to CPFX against P. aeruginosa. Two patients with acute pharyngitis and acute bronchitis were successfully treated by administration of 400mg b.i.d. a day of NM441, a prodrug of NM394. No significant side effects or abnormalities of laboratory data were detected after administration of NM441.