Isoniazid-Associated Hepatitis

In February 1970, 2,321 Capitol Hill employees who were reactors to tuberculin began isoniazid chemoprophylaxis. During the following 9 months, 19 of these employees manifested clinical signs of liver disease. In 9 of the 19, illness began within the first 60 days of isoniazid therapy; the other 10 became ill during the ensuing 6 months. Symptoms included fatigue, anorexia, fever, and gastrointestinal distress; 13 of the 19 were jaundiced, and 2 died. Ten of the patients were women and 9 were men; their mean age was 49.4 years. They could not be linked by person-to-person contacts or by common associations except that each one had taken isoniazid before onset of hepatitis. In a matched comparison group of 2,154 Capitol Hill employees who were unreactive to tuberculin and had not taken isoniazid, hepatitis developed in only one during the same 9-month period. Hepatitis did not occur during this same period in any of 260 tuberculin reactive employees who had declined isoniazid therapy. Although the incidenc...