Late-phase-II clinical study of gatifloxacin, an oral new quinolone, in respiratory tract infections

We investigated the clinical and bacteriological efficacy, safety, usefulness, and fluid concentrations of gatifloxacin (GFLX) in respiratory tract infections. GFLX was administered in once-daily or twice-daily doses of 100, 150, or 200 mg for up to 7 days in cases of acute bronchitis and for up to 14 days in cases of chronic respiratory infection and pneumonia. The results were as follows: 1. Clinical efficacy was evaluated in 87 cases, of whom 83 received twice-daily and 4 once-daily doses. The overall clinical efficacy rate (excellent or good) was 92.0% (80/87). 2. Bacteriological efficacy was evaluated in 34 cases of identified bacteria. The eradication rate was 91.2% (31/34). 3. Side effects were evaluated in 97 cases, and their incidence was 6.2% (6/97). Laboratory test findings were evaluated in 84 cases, and the incidence of abnormal findings was 11.9% (10/34). 4. Clinical usefulness was evaluated in 89 cases. The usefulness rate (very useful or useful) was 84.3% (75/89). 5. Serum and sputum concentrations of GFLX were measured in one case of chronic respiratory-tract infection after the 5th and 9th doses of 200 mg twice daily. The sputum to serum concentration ratios were 1.60 and 2.38, respectively. These results indicate good clinical and bacteriological efficacy for GFLX and suggest a satisfactory penetration into sputum. Therefore, it was concluded that GFLX, 100 to 200 mg twice daily, is a useful and satisfactory antimicrobial drug for the treatment of respiratory tract infections.