The effect of tramadol and meloxicam, alone and in combination on oxidative stress status in dogs

Management of pain by different therapeutic agents has always been one of the most important components in clinical veterinary care. Concerns about various side effects of analgesics drugs have lead the pain relief to combination drug therapy. The present study was performed to evaluate the effect of combined tramadol and meloxicam on oxidative stress status in dogs. Twenty clinically healthy dogs were randomly divided into four groups and administered with placebo, tramadol, meloxicam, and combined meloxicam with tramadol for 10 days. The antioxidant enzymes (superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), total antioxidant capacity (TAC), and malondialdehyde (MDA) were assayed in blood samples which were collected in days 0, 5, 10, 15, and 20. In dogs administrated with tramadol, the antioxidant enzymes and TAC were significantly decreased and MDA level was significantly increased. However, meloxicam group showed no alteration in the levels of GPx, CAT, TAC, and MDA. Moreover, administration of meloxicam with tramadol improved oxidative stress status through inhibiting lipid peroxidation, increasing antioxidant enzymes, and TAC. These results indicate that meloxicam is effective in reducing oxidative stress induced by tramadol. Therefore, combination of tramadol and meloxicam is desired due to their potential analgesic result and ameliorating effect on oxidative stress status.