Hepatotoxicity from isoniazid and rifampin among children treated for tuberculosis.

To estimate rates of hepatotoxicity in the United States among children treated for tuberculosis, we conducted a retrospective survey of health departments and individual practitioners. We received 874 reports suitable for analysis of children treated during 1977 to 1979. A total of 16 hepatotoxic reactions were reported; 14/430 (3.3%) children receiving isoniazid and rifampin had a hepatotoxic reaction, which approximates the rate seen in adults taking these drugs. Half of the reactions occurred during the first month of therapy, and all of the well-documented reactions were noted during the first 10 weeks. Because the likelihood of hepatotoxicity may be increased with higher drug doses, limiting the dose of isoniazid to 10 mg/kg and that of rifampin to 15 mg/kg may help minimize hepatotoxic reactions. Because more serious disease, especially disseminated tuberculosis, may further increase the risk of hepatotoxicity, close monitoring of such children receiving isoniazid and rifampin should help minimize serious hepatotoxicity. Routine biochemical monitoring may not be necessary for all children, eg, those with mild forms of disease and those with normal pretreatment liver function who are treated with lower drug doses.