<qa>  What is MFX?Moxifloxacin MFX is a fluoroquinolone with a high in vitro and in vivo bactericidal activity against Mycobacterium tuberculosis. A daily dose of 600-800 mg MFX should be considered for optimal killing of the involved mycobacteria and suppression of drug resistance, which is higher than the currently used dose of 400 mg once daily. In general, safety data to support switching to the suggested higher dose are limited. 