ANTIMYCOBACTERIAL DRUGS

Mycobacterial infections are the most difficult of all bacterial infections to cure. Mycobacteria are slowly growing organisms (can also be dormant) and thus completely resistant to many drugs, or killed only very slowly by the few drugs that are active. The lipid-rich mycobacterial cell wall is impermeable to many agents. A substantial proportion of mycobacterial organisms are intracellular, residing within macrophages, and inaccessible to drugs that penetrate poorly. Finally, mycobacteria are notorious for their ability to develop resistance to any single drug. Combinations of drugs are required to overcome these obstacles and to prevent emergence of resistance during the course of therapy. The response of mycobacterial infections to chemotherapy is slow, and treatment must be administered for months to years depending on which drugs are used. Antimycobacterial drugs can be devided into three groups: drugs used in the treatmen of tuberculosis, drugs used in the treatment of atypical mycobacterial infection, and drugs used in the treatment of leprosy.