Evaluation of Risk Factors for Development of Anti-Tubercular Therapy Induced Hepatotoxicity: A Prospective Study

Background: Incidence of Antitubercular Therapy (ATT)-induced hepatotoxicity is higher in India when compared to Western countries. As the occurrence of ATT-induced hepatotoxicity is unpredictable, serial intensive monitoring of hepatic function is now being recommended by the American Thoracic Society in individuals at high risk. This study was done to evaluate the risk factors for the development of ATT induced hepatotoxicity in India.

Methodology: In this prospective, observational study, patient characteristics of microbiologically/ radiologically/ histopathologically confirmed tuberculosis were prospectively compiled. Serial liver function tests were done once a month in all patients. Patients who developed ATT-induced hepatotoxicity were considered as the study group and those who did not develop the event as a control group. The primary outcome measure was to estimate the hazard ratios associated with risk factors for the development of ATT induced hepatotoxicity. Cox Regression Analysis was done using SPSS 20.

Results: A total of 200 patients were enrolled in the study, of them, 14% developed ATT-induced hepatotoxicity and 86% did not develop the event. The baseline liver function tests in the study group and control group were within normal limits. Female gender, alcoholism, HIV co-infection and age >35 yrs were identified to have a higher risk for development of ATT-induced hepatotoxicity, while cases with pulmonary tuberculosis were found to be at lower risk of developing event.

Conclusion: Intensive liver function monitoring needs to be done in patients with these risk factors, female gender, alcoholism, HIV co-infection, extra-pulmonary tuberculosis and age >35 yrs.