Basic and clinical studies on the efficacy of grepafloxacin

A newly developed pyridone carboxylic acid antimicrobial drug, grepafloxacin (GPFX), was studied basically and clinically. 1) The minimum inhibitory concentrations (MICs) of GPFX against 242 strains of 10 clinically isolated species were determined, and the MICs of ofloxacin (OFLX), ciprofloxacin (CPFX) and tosufloxacin (TFLX) were determined as controls. The antibacterial activity of GPFX was better by 1~4 grades than the control drugs against gram-positive cocci. The antibacterial activity against gram negative bacilli was superior to that of OFLX, although it was slightly inferior to those of CPFX and TFLX. Against Proteus spp., however, GPFX was inferior to the control drugs. 2) GPFX was orally administered to 12 patients consisting of 3 with pneumonia, 5 with acute bronchitis, and 4 with chronic bronchitis at a dose of 100~300 mg once or twice a day for 4~25 days. GPFX was effective in 9 patients, slightly effective in 1, and ineffective in 2, the rate of efficacy being 75.0%. All of 7 strains isolated from 5 patients were eradicated. Adverse reactions were observed in three patients; one had nausea and anorexia, one had dizziness, and the other had dizziness, nausea and anorexia. Elevations of GOT and GPT were observed in one patient, and eosinophiliawas observed in another on clinical laboratory tests.