The challenge of the new tuberculosis drugs

Tuberculosis (TB) continues to cause more deaths worldwide than any other single infectious disease. Even though tuberculosis appears to be decreasing in incidence globally for some time, the proportion of drug resistance is increasing, contributing to greater complexity, morbidity and mortality as well as cost. Since the advent of rifampicin in the 1960s, and the implementation of standard quadruple anti-tuberculosis regimen in the late 1970s, no new drugs have been changed the first line regimen. This regimen is effective however it is pill burden, and duration has not received investment and innovation. Drug-resistant regimens are long and frequently poorly tolerated due to significant toxicity. This review is an update on what is new in the treatment of drug-susceptible and drug-resistant tuberculosis, new TB drugs currently being used and studied in clinical trials are also mentioned. Fortunately, there have been many significant advances in this field in recent years. The horizon is changing with the new WHO shorter multidrug-resistant tuberculosis regimens and with the increasing availability of new or repurposed drugs like bedaquiline, delamanid, clofazimine and linezolid. These drugs pose new challenges relating to their rational use to prevent selection of resistant strains of Mycobacterium tuberculosis even before a new regimen has been studied. The availability of these new drugs is offering hope and new possibilities for saving patients who had few or no treatment options. Their use and combination into effective regimens need to be studied; trials are in progress. It is hoped that soon we will be able to treat sensitive and drug-resistant cases with a universal regimen, this would revolutionise treatment and take us another step closer towards elimination.