Treatment for Mycobacterium tuberculosis must be lengthy because populations of this bacillus differ in metabolic activity, and it must include various associated drugs, since spontaneous chromosome mutations can give rise to drug resistance. The multiresistant phenotype emerges with sequential acquisition of mutations in several independent loci. Thus, the main challenges in tuberculosis treatment are resistant strains and reductions in treatment duration and dose to facilitate adherence on the part of the patient. The drugs should be fast acting, active against resistant strains, and able to eradicate slowly metabolizing populations. Progress in recent years has led to the development of analogs of first-line antituberculosis drugs with longer dosing intervals (rifamycin derivatives) or shorter treatment courses (moxifloxacin, gatifloxacin). Nonetheless, new drugs that additionally have novel mechanisms of action and no cross-resistance to current first-line drugs are needed. This review describes the characteristics, activity, resistance mechanisms, and side effects associated with antituberculosis drugs.