The Jewish Hospital of St. Louis therapeutic grand rounds number 10. Chemoprophylaxis of tuberculosis.

Isoniazid therapy has been proved an effective means of preventing overt clinical tuberculosis in persons with positive tuberculin skin tests, persons who are close contacts of active cases, and persons with inactive tuberculosis that were never treated. The administration of isoniazid in standard dosage for one year in these situations will help greatly to reduce tuberculosis as a community health problem in the future. Studies in recent years, however, point to hepatic dysfunction as a complication of isoniazid therapy in up to 10% of patients. In a few patients, liver disease as a complication of this therapy has been fatal. The likelihood of this complication increases with age. Accordingly, isoniazid chemoprophylaxis should be undertaken with the understanding that the patient has to be followed up closely, especially for evidence of liver disease during the course of therapy. This potentially serious side effect suggests that isoniazid chemoprophylaxis should be used primarily with patients in high risk groups.