Anti-Mycobacterium tuberculosis activities of new fluoroquinolones in combination with other antituberculous drugs

Objectives: Studies were undertaken in order to assess the anti-Mycobacterium tuberculosis (MTB) activities of newly developed fluoroquinolones in combination with other antituberculous drugs. Methods: A new C-8-methoxyl fluoroquinolone, gatifloxacin (GFLX), and a new C-8-chloro fluoroquinolone, sitafloxacin (STFX), in combination with other drugs were examined for their activities against extracellular growing MTB organisms and those replicating in RAW264.7 macrophages (RAW-Mphis). Results: STFX but not GFLX potentiated the activities of rifampin and rifalazil against extracellular MTB. Both GFLX and STFX exhibited combined activities against intramacrophage MTB, when used in combination with rifampin, rifalazil, isoniazid, pyrazinamide, ethambutol, streptomycin, or clofazimine. Conclusions: Although the observed combined effects varied to sonic extent from case to case depending on drug combinations, the present findings suggest the usefulness of these new fluoroquinolones in multi-drug. regimens for tuberculosis patients. (C) 2002 The British Infection Society.