The goal of present work was investigation of putative link between level of isoniazid and its principal metabolite acetylisoniazid with the level of pro- and antioxidant systems markers in patients with pulmonary tuberculosis (TB). Isoniazid, acetylisoniazid, diene conjugates (DC) level and catalase activity were detected in venous blood 2, 4, 6 and 24 hrs. after ingestion of standard dose of isoniazid.
Isoniazid concentration in TB-patients was in reverse correlation with DC level and in direct correlation with catalase activity. Increasing of acetylisoniazid level 4 hrs after isoniazid administration associated with raising of markers of lipids peroxydation. The obtained data witnessed that toxic effect of isoniazid partially can be explained by production of acetylisoniazid.