**Miscellaneous**

**Chapter 16**

**Research and Development of New Drugs Against**

Tuberculosis (TB) is a contagious infectious disease caused byspecies belonging to the *Mycobac‐ terium tuberculosis* complex. At present, it is a re-emerging disease, due to co-infection with the Human Immunodeficiency Virus (HIV), but also to global bacterial resistance, and lack of adequate treatment in some places in the world. Approximately one third of the world's population is infected with *M. tuberculosis*, and out of these people, about 1.1 million people die every year of TB [1], making this disease the main cause of bacterial infectious death in adoles‐ cents and adults all around the world. In 2010 there was an estimation of 8.8 million incident cases and 12.0 million prevalent cases of TB worldwide. *M. tuberculosis* drug-resistant isolates haveappearedgivingorigintomultidrug-resistant(MDR)andextensivelydrug-resistant(XDR) strains. XDR-TB has been identified in every continent of the planet. By 2010, the World Health Organization (WHO) was notified of the existence of 53.018 cases of multi-drug resistant TB (MDR-TB) worldwide; figure that only represents 18% of the TB-MDR estimated cases among reported pulmonary TB cases around the world [1]. Currently, there is global alarm since the infection with these strains is cured only in 66% of MDR cases and in 60% of the XDR cases [2]. More than sixty years ago, the introduction of the first anti-TB drugs for the treatment of TB (streptomycin (STR), *p*-aminosalcylic acid (PAS), isoniazid (INH) and then later ethambutol (EMB) and rifampicin (RIF)) gave optimism to the medical community, and it was believed that the disease would be completely eradicated soon. After a 30-year halt of anti-TB drug Research & Development pipeline, the Global Alliance for TB Drug Development (TB Alliance) started to fill the gap between the existing chemotherapeutics and the clinical need. Despite the efforts carried out with candidates in clinical trials such as PA-824 and bedaquiline, there is an urgent need of in-depth medicinal chemistry discovery studies for assuring enough leads

> © 2013 Guzman et al.; licensee InTech. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

and reproduction in any medium, provided the original work is properly cited.

© 2013 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution,

Juan D. Guzman, Ximena Montes-Rincón and

Additional information is available at the end of the chapter

**Tuberculosis**

Wellman Ribón

**1. Introduction**

http://dx.doi.org/10.5772/54278
