Multicenter open-label phase II/III study of intravenous levofloxacin in subjects with respiratory tract infection

This open-label study evaluated the efficacy and safety of an injectable preparation of levofloxacin(LVFX), a quinolone antibacterial, in the treatment of respiratory tract infection(RTI). Subjects with community-acquired pneumonia or secondary infection of chronic respiratory disease were enrolled and treated with LVFX administered at 500 mg once daily by intravenous infusion for 7-14 days. Clinical efficacy: Of 181 evaluable subjects with RTI, 173 (95.6%) showed a clinical response at the end of treatment. Clinical response rate by diagnosis was 95.9% (140/146) for community-acquired pneumonia and 94.3% (33/35) for secondary infection of chronic respiratory disease. A clinical response was achieved in 35/35 subjects (100%) with isolates of Streptococcus pneumoniae the predominant RTI causative organism. Bacteriological efficacy: Bacteriological response rate per subject was 97.6% (80/82) and overall pathogen eradication rate was 97.8% (91/93), at the end of treatment. Safety: The adverse drug reaction incidence was 44.2% (91/206) in the overall population and 25.0% (4/16) in the elderly (≥80 years of age). Adverse drug reactions reported in at least 5% of those treated and evaluable for safety included injection site erythema (13.6% [28/206]), ALT increased (9.7% [20/206]), and AST increased (8.7% [18/206]). Injection site reactions - erythema, pruritus, pain, swelling, and induration - were especially frequent, occurring in 34 of 206 subjects (16.5%). All injection site reactions were mild and resolved within the day of onset without treatment. None required treatment discontinuation. In conclusion, LVFX administered by intravenous infusion at 500 mg once daily for 7-14 days is effective and safe in RTI treatment.