Advances in Tuberculosis: Therapeutics

Excerpt

After discovery of streptomycin, significant improvement occurred over 2–3 decades in treatment of tuberculosis. Effective combination chemotherapy evolved over decades of research, thus dramatically reducing morbidity and mortality due to tuberculosis (TB). Further efforts led to development of modern day short term chemotherapy with high success rate and it appeared that perhaps elimination of TB will be a reality, however this euphoria was short lived. Declining burden in the developed nations saw a u-turn and this resurgence of TB was associated with increasing drug resistant TB. Emergence of human immunodeficiency virus (HIV) further boosted this reversal of trends. World Health authorities had to declare tuberculosis as an emergency in 1993. While the world grappled with rising trends of drug resistance TB, the treatment success rates for multi drug resistant (MDR) TB were poor as there were no new anti-tuberculosis drugs and the second-line or reserve drugs used were less efficacious and more toxic then the first-line drugs. Since then, efforts are being made to optimize the therapy with first-line drugs to prevent occurrence of drug resistance and to develop new drugs or to find repurposed drugs for creating a potent second-line therapy. It is only in past about 5 y that drugs like Bedaquiline and Delanamid have come up as new drugs effective against Mycobacterium tuberculosis. Very recently, WHO has used individual patient data from several countries to categorise and devise the drug therapy for multi drug resistance (MDR) and extreme drug resistance (XDR) in TB. Studies have been commissioned to understand the TB pharmacology and microbiology so as to improve the outcome of drug sensitive as well as drug resistant tuberculosis with minimal side-effects. …