Antituberculous agents.

Antituberculous agents have radically improved the prognosis of patients with active tuberculosis. Generally, 6-month and 9-month antituberculous regimens have been successful, and surgical therapy is rarely needed. Extrapulmonary tuberculosis should be managed with the same drug regimens as pulmonary tuberculosis. The major cause of therapeutic failure is poor compliance of the patient in taking the prescribed medication regularly. A second cause of failure of treatment is resistance of tubercule bacilli to antimicrobial agents used. When failure of treatment is apparent, careful reassessment by physicians experienced in the treatment of tuberculosis is indicated. A single drug should never be added to a failing regimen. Isoniazid administered prophylactically for 6 to 12 months is effective in most cases.