Prevalence and risk factors of anti-tuberculosis drug-induced hepatitis in Malaysia.

INTRODUCTION Tuberculosis (TB) affects one-third of the world's population. Anti-TB drugs with isoniazid, rifampicin and pyrazinamide are very effective but they can cause hepatotoxicity. Many risk factors have been recognised. Data on prevalence of anti-TB drug-induced hepatitis as well as the contributing risk factors are scarce in Malaysia. This observational case control study was designed to look at the prevalence and the risk factors of drug-induced hepatitis in our population. METHODS We retrospectively examined all the case notes of anti-TB drug-induced hepatitis over a 30-month period from January 2003 to June 2005. They were compared with controls selected by simple random sampling. Both groups were compared in terms of demographical data and risk factors, such as age, gender, body mass index, hepatitis B carrier, human immunodeficiency virus (HIV) infection, sites of TB, and pretreatment liver biochemistries (serum albumin, globulin, aspartate aminotransferase, alanine aminotransferase and bilirubin). Data was evaluated by chi square, independent t-test (univariate) and binary logistic regression analysis (multivariate). RESULTS Out of 473 TB patients, 46 developed hepatitis and 138 were selected as controls. The prevalence of drug-induced hepatitis was 9.7 percent. On univariate analysis, HIV infection (p-value is 0.005), extrapulmonary tuberculosis (p-value is 0.008), lower serum albumin (p-value is 0.023) and higher serum globulin (p-value is 0.025) were significant risk factors. On binary logistic regression, only HIV infection (p-value is 0.018) and extrapulmonary TB (p-value is 0.017) were significant. CONCLUSION The prevalence of hepatitis was 9.7 percent. The presence of HIV infection and extrapulmonary TB were significant risk factors for the development of hepatitis.