Abstract
We investigated pazufloxacin (PZFX), a newly developed oral quinolone, for its antimicrobial activity, for its pharmacokinetics in the plasma and sputum, and for its clinical efficacy on respiratory infections. The results were as follows.
1. Antimicrobial activity: Minimal inhibitory concentrations of PZFX against 740 strains of 18 species isolated from clinical specimens (170 strains of gram-positive cocci, 319 of enterobacteria, 125 of glucose non-fermenting gram-negative rods, 49 of Moraxella catarrhalis, 52 of Haemophilus influenzae, 25 of Bacteroides fragilis) were determined according to the standard method prescribed by the Japan Society of Chemotherapy, and compared with those of tosufloxacin (TFLX), ofloxacin (OFLX) and lomefloxacin (LFLX). The overall antimicrobial activity of PZFX was superior to OFLX and LFLX, and almost equal to or slightly less than TFLX.
2. Blood and sputum levels
When 200 mg of PZFX was orally administered to a patient with bronchiectasis (48 years old, male, 50kg) after meals, the maximum blood concentration was 3.38μg/ml at 4 hours, and the maximum level in sputum was 1.35μg/g. The rate in sputum against the maximum blood concentration of PZFX was 39.9%.
3. Clinical results
PZFX was administered to 4 patients with respiratory infections at a dose of 200-600 mg a day for 7-14 days. The clinical efficacy was good in all patients. No side effects or abnormal laboratory findings were observed.
