Suggested indications for baseline and serial liver function testing among nonpregnant adults undergoing treatment for tuberculosis infection with isoniazid or a rifamycin

Treatment regimens for tuberculosis infection regimens are potentially hepatotoxic. Patients at risk for hepatitis should have liver enzyme testing performed before starting treatment and monthly while on therapy. In addition, patients should be informed of the signs and symptoms of hepatitis and advised to stop therapy and seek prompt evaluation should they occur. In general, treatment should be discontinued for symptomatic patients with serum transaminase levels greater than three times the upper limit of normal or for asymptomatic patients with serum transaminase levels greater than five times the upper limit of normal.