Abstract
We evaluated the usefulness of temafloxacin (TMFX), a new quinolone derivative, in respiratory tract infections. The MIC of TMFX for 70% of methicillin-sensitive Staphylococcus aureus was 0.10μg/ml. It was 50μg/ml for methicillin-resistant S. aureus, 0.78μg/ml for Streptococcus pneumoniae, 0.05μg/ml for Haemophilus influenzae, 0.05μg/ml for Branhamella eatarrhalis, 6.25μg/ml for Pseuaomonas aeruginosa and 0.10μg/ml, for Klebsiella pneummiae 0.10μg/ml. The activity was comparable with or superior to that of ofloxacin (OFLX).
The pharmacokinetics of TMFX were studied in four chronic respiratory patients. The maximum sputum levels in two patients during a 150mg oral administration two times per day were 0.86μg/ml and 1.05μg/ml. The maximum sputum, levels in two patients after an administration of 300mg were 2.40μg/ml and 3.00μg/ml, and the peak ratio (maximum sputum level/maximum serum level) was 100%. The serum elimination half-lives in two patients were 7.1 hours and 9.9 hours.
Nineteen patients with lower respiratory tract infections were studied for clinical evaluation of TMFX. TMFX was given orally at 300-600 mg per day for 3-14 days. The causative organisms were S. pneumoniae (4 cases), H. influenzae (4 cases), B. catarrhalis (6 cases), P. aeruginosa (4 cases) and Escherichia coli (1 case). The rate of clinical response was 78.9%. The rate of bacterial elimination in sputum samples was 76.5% (4 strains of P. aeruginosa were not eliminated). No reverse effect was observed.
The effects of subMlCs of TMFX and OFLX on a fimbriate strain of B. catarrhalis from a patient with chronic respiratory tract infection was observed by transmission electron microscopy. Abnormal fimbriae were observed in 29% of B. catarrhalis at 1/2 MIC of TMFX, 3% at 1/4 MIC and 1% at 1/8 MIC. No abnormal fimbriae were observed at subMlCs of OFLX. We concluded that TMFX is a very useful oral antimicrobial agent for the treatment of respiratory tract infections.
