Basic and clinical studies of pazufloxacin in respiratory infections

Basic and clinical studies were performed on a new quinolone antimicrobial agent for oral use, pazufloxacin (PZFX). The results were as follows. 1. Antimicrobial activity: The minimal inhibitory concentrations of PZFX against 515 clinical isolates including 16 different species were measured and compared with those of ofloxacin, norfloxacin and ciprofloxacin. PZFX showed good antimicrobial activity against gram-positive and-negative bacteria. 2. Blood and sputum concentrations: A single dose of 200 mg and 100 mg of PZFX was orally administered after a meal to 4 patients and 1 patient, respectively. The blood and sputum concentrations of PZFX were measured by high pressure liquid chromatography. In 4 patients given 200 mg, the peak concentrations in blood and sputum were 1.80 ∼ 3.20 μg/ml at 2 ∼ 4 hours after administration and 0.57 ∼ 1.09 μg/g at 2 ∼ 5 hours, respectively, suggesting that PZFX had good penetration into sputum. 3. Clinical efficacy: PZFX was administered to 14 patients with respiratory infections and 1 patient with urinary tract infections, and its clinical efficacy and side effects were investigated. The efficacy rate was 85.7% in the respiratory infection group (excellent in 2, good in 10, and poor in 2). Abnormal findings in clinical testing were mild elevation in GOT and GPT, and in BUN and s-Cr in 1 patient each. These abnormal changes improved after completion of treatment, and the safety of PZFX was confirmed. No side effects were observed.