Clofazimine: A useful antibiotic for drug-resistant tuberculosis.

Drug resistance is still the major threat to global tuberculosis (TB) control, and drug-resistant (DR) Mycobacterium tuberculosis (M. tuberculosis) strains have become the main challenge worldwide. Currently used antibiotics for treatment of DR-TB are often poorly tolerated and not sufficiently effective. Since the therapeutic options are still limited, the main strategy for treatment of DR-TB is to repurpose existing anti-mycobacterial agents. Clofazimine (CFZ) is one such drug that has recently attracted interest against DR-TB. CFZ is a hydrophobic riminophenazine that was initially synthesized as an anti-TB antibiotic. Although the mechanisms of action of CFZ are not yet entirely understood, it has been suggested that outer membrane is its primary action site, and the respiratory chain and ion transporters are the putative targets. In this review, we will discuss the anti-mycobacterial properties of CFZ, and provide new insights into the clinical use of this drug.