Recent therapeutic approaches for the management of tuberculosis: Challenges and opportunities

Tuberculosis is a highly contagious disease spread by Mycobacterium tuberculosis. It is responsible for highest numbers of death and soon will surpass the deaths caused by HIV. The pandemic disease causes, estimated 10.4 million new infections, among which 5.9 million were men, 3.5 million were women, 1.0 million were children and the HIV patients co-infected with tuberculosis accounted for 1.2 million of all new cases in 2015, alone. The increased number of drug resistant (MDR/XDR) strains and the failure of the conventional regimens against this strain are the challenges of the coming decades. The goals of new therapeutic approaches are to ensure cure without relapse, to inhibit deaths, contagions and the formation of drug-resistant strains. The main approaches of anti-tubercular therapy involves either development of new chemical entity with a novel mechanism of action or repurposing of old drugs which show significant activity on drug-resistant strains. Repurposing existing drugs is a promising alternative to the expensive and time-consuming process of drug discovery. A number of carrier-based drug delivery systems incorporating the principal anti-tuberculosis drug has been developed to provide targeted action with reduced dosing frequency in order to improve the patient compliance which is a major reason for therapeutic treatment failure. This article reviews the recent approaches to the treatment of tuberculosis in terms of discovery of new chemical entity, repurposing of old drugs and the use of novel drug delivery technology such as liposomes, niosomes, liquid crystals, solid lipid nanoparticles, polymeric micelles, dendrimers, nanoemulsion, nanosuspension, silica nanoparticles, polymeric nanoparticles and microparticles for complete eradication of Mycobacterium tuberculosis.