The evaluation of analgesic effects of milnacipran and sertraline in tail-flick test.

Introduction: Antidepressant drugs are used in the treatment of pain as an adjuvant or alone. It has been shown that antidepressant drugs have analgesic effects in various diseases (diabetic neuropathy, low back pain, cancer pain etc.) Sertraline is a potent serotonin re-uptake inhibitor. Some antidepressant drugs inhibited both of the reuptake of serotonin and of noradrenaline. These drugs are called serotonin-noradrenaline re-uptake inhibitors (SNRIs). Milnacipran is a serotonin-noradrenaline re-uptake inhibitor. We have studied the analgesic effects of sertraline and milnacipran after acute and chronic application in tail-flick test in mice.
Methods: The analgesic effects of milnacipran (10, 30, 50 mg/kg) and sertraline (10, 20, 50 mg/kg) were measured after acute and chronic application in tail flick test. The analgesic effects of milnacipran (30 mg/kg) or sertraline (50 mg/kg) were evaluated after the application of L-NAME (10 mg/kg), naloxone (5 mg/kg), prazosin (1 mg/kg), ondansetron (0.1 mg/kg) in tail flick test.
Results: Milnacipran (30 mg/kg) and sertraline (50 mg/kg) produced statistically significant analgesic effect compared to their control values after acute and chronic application in tail-flick test. The analgesic effects of both milnacipran (30 mg/kg) and sertraline (50 mg/kg) in the presence of L-NAME (10 mg/kg), naloxone (5 mg/kg), ondansetron (0.1 mg/kg) and prazosin (1 mg/kg) were inhibited in tail-flick test.
Conclusion: These results indicate that the analgesic effects of milnacipran and sertraline are related to nitrergic, opioidergic, serotonergic and adrenergic system (Fig. 8, Ref. 23).