study on the hepatotoxicity of anti-tuberculosis drugs in 190 patie nts with pulmonary and e xtrapulmonary tuberculosis

tuberculosis is one of the oldest diseases that affects humans. the cause of this disease is mycobacterium tuberculosis. this disease affects approximately 8.8 million people worldwide and led to over 3 million deaths in 1995. 95% of those affected and 98% of deaths occurred in developing countries. hepatic reactions constitute a major proportion of drug reactions to antituberculosis drugs being reported in 4% of cases treated with rifampin/isoniazid and pyrazinamide in the us a and 8-50% in india and developing countries. for the purpose of identifying the hepatotoxicity of anti-tuberculous drugs, this study was performed in hospitals affiliated to shahid beheshti university in tehran during 1994 to 1997. the current descriptive study was performed on hospitalized patients diagnosed as having active tuberculosis. history was taken from all the patients and clinical signs were recorded. three sputum samples for mycobacterial acid fast stain examination and cultures (three consecutive days) were sent to pasteur institute. liver function tests (ast, alt, alkaline phosphatase, bilirubin, pt) were performed before treatment and repeated weekly for two weeks then two weekly for the first two months and then monthly until the end of treatment. from a total of 262 patients during the study, 190 patients were studied. 51 % were male and the rest were female. the lowest rate of tb was in the age group less than 5 and the most frequent rate oftb was in the 56-65 years age group. 107 patients (56.2%) had active pulmonary tuberculosis and 43.7% had extra-pulmonary tb. 44.2% had positive smear sputum, 22.1 % had positive biopsy, and 33.6% were diagnosed based on clinical findings, xrays and other paraclinical tests. 25.7% of patients had increased alt and ast following the treatment, and in 4.7% of cases the increase was 4-5 times normal and in 3.6% 5 times normal, 8.4% had increase in bilirubin and 6.8% had increase in bilirubin associated with increase in alt and ast, 8.4% had increased alkaline phosphatase and 7.6% had disturbance in pt. considering that 25.7% of the patients had increased levels of liver enzymes and in 3.6% of them the increased level exceeded 5 times that of normal and also 6 cases of 7 were over 35 years old, therefore, anti-tuberculosis drug consumption, must be considered more seriously in patients over the age of 35.