Liver function tests during treatment of tuberculosis with short-course regimens containing isoniazid, rifampicin & pyrazinamide

Serial liver function tests (aspartate amino transferase–AST, alanine amino transferase– ALT and total bilirubin) were undertaken in patients admitted to controlled clinical trials for the treatment of tuberculous meningitis and pulmonary tuberculosis. In patients with tuberculous meningitis, daily treatment with isoniazid 20 mg/kg in addition to rifampicin 12 mg/kg resulted in a significant increase in the activities of both AST and ALT; there was no appreciable change with regimens containing isoniazid 12 mg/kg. In two studies on pulmonary tuberculosis, there was a significant increase in the activities of both enzymes following 2 or 3 months of treatment with daily streptomycin, isoniazid and pyrazinamide with or without rifampicin. No appreciable differences were observed between patients who received rifampicin and those who did not and also between slow and rapid acetylators of isoniazid. Serum total bilirubin showed a significant decrease following treatment for 2 months with a daily regimen containing rifampicin in patients with tuberculous meningitis and also in those with pulmonary tuberculosis. A comparison of patients who developed jaundice during treatment with anti-tuberculosis drugs and others who had jaundice presumably due to infective hepatitis revealed lower mean values for total bilirubin, AST and ALT in the former group (by 48–64%) than in the latter (P < 0.02). There was, however, considerable overlap between the two groups in the distributions of all parameters.