Abstract
The minimum inhibitory concentration (MIC) of pazufloxacin (PZFX) for Streptococcus pneumoniae was determined. The therapeutic efficacy on respiratory and urinary tract infections were also evaluated. The results were as follows:
1. The MIC of PZFX for S. pneumoniae isolated from blood, sputum, pharyngeal secretion and otorrhea was determined by agar plate dilution method and compared with those of other drugs. The MICH and MIC90 of PZFX against both penicillin-sensitive S. pneumoniae (PSSP) and penicillin-insensitive S. pneumoniae (PISP) were 3.13 μg/ml and 6.25 μg/ml, respectively. The MIC50 and MIC90 of tosufloxacin (TFLX) against PSSP were 0.2 μg/ml and 0.39 μg/ml, respectively, and those against PISP were 0.2 μg/ml and 0.2 μg/ml, respectively. Thus, it was found that the antimicrobial activity of TFLX against both PSSP and PISP was four times stronger than that of PZFX. The MIC of PZFX against strains which were highly resistant to PCG ranged from 3.13 to 6.25 μg/ml. There was no cross resistance between PZFX and PCG in PISP.
2. PZFX was administered to 18 patients with respiratory tract infections and 2 patients with urinary tract infections. The clinical effects could be evaluated in 19 patients except one with pyelonephritis. Excellent or good clinical response was obtained in 2 of 2 patients with pneumonia, 10 of 11 patients with chronic bronchitis, 4 of 4 patients with bronchial asthma with infection, one patient with pulmonary emphysema with infection and one patient with pyelonephritis, with an overall efficacy rate of 94.7%(18/19). Causative bacteria were identified in 3 patients. At the end of the therapy, Erwinia agglomerans persisted in a patient with chronic bronchitis. In another patient with pyelonephritis, all the strains of Pseudomonas aeruginosa, Morganella morganii, Enterococcus faecalis, Proteus mirabilis and Klebsiella pneumoniae were eradicated. Bacteriological effect remained unknown in a patient with pseudomonas urinary tract infection who was excluded from clinical evaluation. With regard to side effect, an eruption accompanied with eosinophilia was observed in a patient on the fourth day of the treatment, and the drug was withdrawn.
