Novel agents in the management of Mycobacterium tuberculosis disease

The goals of tuberculosis control are to cure active disease, prevent relapse, reduce transmission and avert the emergence of drug resistance. However, since the 1960s, there have been few developments in available therapies. Currently available agents are complicated by numerous side-effects, drug interactions and the need for a long duration of therapy. Rifampicin-containing regimes lead to hepatic enzyme induction which can complicate or preclude the use of protease inhibitors and non-nucleoside reverse transcriptase inhibitors in patients infected with the human immunodeficiency virus. Furthermore, emerging drug resistance has complicated management for many patients and clinicians. Therefore, new chemotherapeutic agents are urgently needed. Existing antimicrobials are emerging as potent antituberculous agents. Recent studies have demonstrated the antituberculous activity of newer fluoroquinolones including levofloxacin, moxifloxacin, and gatifloxacin. Their use as first line antituberculous agents is currently under investigation. Furthermore, the oxazolidinones linezolid and PNU-100480 have been shown to have antituberculous activity in addition to their antibacterial effects. Several other agents are currently being developed for the treatment of tuberculosis. These agents include diarylquinolones (R207910), nitroimidazopyrans (PA-824, OPC-67683), ethambutol analogues (SQ109), cerulenin, trans-cinnamic acid, macrolides, pyrroles (LL3858), long-acting rifamycins and inhaled interferon-gamma. Furthermore, vaccines are being explored for pre-exposure and post-exposure use. This review will describe therapeutic developments in the management of tuberculosis, highlighting mechanisms of action of new pharmacological agents and their potential for clinical use.