Evaluation of Risk Factors for Antituberculosis Treatment Induced Hepatotoxicity (Report‪)‬

In 1993, the World Health Organization (WHO) declared tuberculosis (TB) to be a 'global emergency' with more than a third of the world's population infected. Globally, 8.9 million new cases of TB occur annually, of which 1.8 million (20%) occur in India (1). Anti-TB chemotherapy containing isoniazid (H), rifampicin (R) and pyrazinamide (Z) has proved to be highly effective but hepatotoxic. Anti-TB drug induced hepatotoxicity (DIH) is the most common side-effect leading to interruption of therapy (2). Risk of anti-TB DIH is increased when these drugs are combined. Wide variations have been found in the reported incidence of hepatotoxicity during short-course chemotherapy. From an analysis of pooled data from four prospective Indian studies (3-6), the risk of clinical hepatitis was calculated to be 11.5 per cent (95% CI 9.51 to 13.51), whereas meta-analysis (7) of 14 published studies from west found the risk to be 4.28 per cent (95% CI 3.38 to 5.28). Several risk factors for hepatotoxicity have been suggested (8) such as advanced age, sex, poor nutritional status, liver disease, inappropriate use of drugs, infection with hepatitis B virus (HBV), hepatitis C virus and human immunodeficiency virus (HIV), acetylator status, and high alcohol intake. We report here the findings of a prospective case-control study done to assess the role of these putative risk factors in the development of hepatitis in patients receiving anti-TB treatment.