Comparative roles of levofloxacin and ofloxacin in the treatment of multidrug-resistant tuberculosis: preliminary results of a retrospective study from Hong Kong.

OBJECTIVE: To compare levofloxacin and ofloxacin in the treatment of multidrug-resistant tuberculosis (MDR-TB). PATIENTS AND METHODS: A retrospective analysis of 106 patients with MDR-TB (February 1990 through December 2000) receiving directly observed therapy with fluoroquinolone and accompanying drugs, which mainly included aminoglycosides, cycloserine, ethionamide/prothionamide, and pyrazinamide, was performed. Clinical data from 99 suitable patients were subjected to univariate analysis, stratification, and multiple logistic regression to compare the roles of levofloxacin and ofloxacin in multidrug regimens.
RESULTS: Forty patients received 612.5 +/- 79.0 mg qd levofloxacin (mean +/- SD), and 59 patients received 628.8 +/- 101.8 mg qd ofloxacin together with similar active second-line drugs for similar durations. The times to sputum smear (both 1.8 months) and culture conversion (both 2.1 months) were equivalent. Adverse reactions occurred at similar rates (10.0% vs 11.9%). The combined treatment success rate was 83.8%, being higher among ofloxacin-susceptible than ofloxacin-resistant cases (90.5% vs 64.0%, p < 0.01). The success rates for the levofloxacin group were 90.0% (overall), 96.2% (ofloxacin-susceptible cases), and 78.6% (ofloxacin-resistant cases) in comparison with 79.7%, 87.5%, and 45.5%, respectively, for the ofloxacin group (Mantel-Haenszel common odds ratio estimate, 4.0; p < 0.05). Bacillary susceptibility to ofloxacin, good adherence, radiographic extent of one lung or less, and use of levofloxacin were independent predictors of favorable outcome (odds ratios, 7.6 to 21.3). One patient each from both groups relapsed.
CONCLUSION: Levofloxacin was found to be more efficacious than ofloxacin when incorporated into multidrug regimens used for treatment of MDR-TB.