Limited Effect of Later-Generation Fluoroquinolones in the Treatment of Ofloxacin-Resistant and Moxifloxacin-Susceptible Multidrug-Resistant Tuberculosis

Recent data conflict on the clinical efficacy of later-generation fluoroquinolones, such as moxifloxacin or levofloxacin, for the treatment of multidrug-resistant tuberculosis (MDR-TB) that is resistant to ofloxacin but susceptible to moxifloxacin. The purpose of the present study was to evaluate whether later-generation fluoroquinolones can improve treatment outcomes in patients with ofloxacin-resistant, moxifloxacin-susceptible MDR-TB. A retrospective cohort study was performed on 208 patients with moxifloxacin-susceptible MDR-TB who were treated between 2006 and 2011. Later-generation fluoroquinolones were used for all patients. Overall, 171 patients (82%) had ofloxacin-susceptible, moxifloxacin-susceptible MDR-TB (ofloxacin-susceptible group), and 37 (18%) had ofloxacin-resistant, moxifloxacin-susceptible MDR-TB (ofloxacin-resistant group). Compared to the ofloxacin-susceptible group, the ofloxacin-resistant group was more likely to have a history of MDR-TB treatment ( P P P = 0.003), streptomycin ( P = 0.015), prothionamide ( P P P P in vitro moxifloxacin susceptibility, the frequency of favorable treatment outcomes for ofloxacin-resistant MDR-TB was significantly lower than that for ofloxacin-susceptible MDR-TB, even when later-generation fluoroquinolones were used, indicating that more-aggressive therapies may be needed for ofloxacin-resistant MDR-TB.