RESUMO
Antituberculous drugs, rifampicin and isoniazid proved to be toxic to the liver and kidneys both biochemically and histopathologically when given singly in a dose of 5.4 mg/l00 gm body weight [b.wt] Intra peritoneally [I.P] twice weekly for two months and their toxic effect became more pronounced when given in combination.Isoniazid proved to be more toxic to the liver as reflected on hepatic enzymes [aspartate aminotransferase AST and alanine aminotransferase ALT] and kidney functions [serum creatinine and blood urea] compared to rifampicin Significant decrease in animals body weights compared to that of the controls was also pronounced with the combination, less with isoniazid and least with rifampicin but internal organs weights were not affected.After termination of therapy recovery of liver and kidney functions occured with rifampicin after one month, with isoniazid after two months and more than two months with the combination therapy