Antinociceptive activity of milnacipran

Pain is one of the most common complaints that leads patients to seek medical care. Epidemiological studies have shown that the depressive symptoms have been appeared at the patients having pain and also the depressive patients frequently complain about the pain syndrome. In addition, various antidepressant drugs have been used as an alternative to narcotic analgesic drugs in chronical painful conditions. These clinical observations suggest a close linkage between depression and pain perception, since an important role in both pathogenesis has been attributed to disturbances of serotonergic and noradrenergic neurotransmission. Efficacies of antidepressants have been demonstrated. Therefore, they have been widely used in the clinical management of pain as well as opioids and other analgesics. In the present thesis, it was investigated by using several analgesia tests whether milnacipran, which is known with the trade name Ixel® and used for the treatment of major depression, has antinociceptive efficacy on mice. Tail-clip, tail-immersion and hot-plate tests were applied to evaluate the central analgesic activity and writhing response test was applied to evaluate peripheral analgesic activity using 10, 25, 50, 75 mg/kg intraperitoneal (i.p.) doses of milnacipran. The analgesic effect of milnacipran was compared to that induced by dipyrone (100 mg/kg) and morphine (5 mg/kg) in these models on mice. According to our findings, when compared to controls, milnacipran has a dosedependent antinociceptive activity. Key Words: pain, antidepressant, milnacipran, depression