Increase in antioxidant activity in procainamide-treated rats

Recent studies suggest that in vivo procainamide oxidation underlies induction of autoimmunity by this drug. Since drug metabolism may be accompanied by generation of reactive oxygen species, plasma and liver thiobarbituric acid reacting substances (TBARS), activity of erythrocyte and liver superoxide dismutase, catalase, selenium-dependent glutathione peroxidase (Se-GPX), and plasma antioxidant activity in procainamide treated rats were evaluated. Procainamide administration increased liver lipid peroxide levels, intensified the activity of liver catalase and erythrocyte superoxide dismutase, as well as plasma antioxidant activity. The remaining biochemical parameters in the treated rats were within control values, except for the decreased erythrocyte catalase activity. We conclude, that the increased activity of free radicals observed in the treated rats could contribute to the development of procainamide induced side effects.