Abstract

Background: Several antidepressants are currently being used as analgesic in neuropathic pain, but their effect on inflammatory pain is not clear. Few studies have shown that duloxetine also has anti-inflammatory effect along with its antinociceptive activity. Aims and Objectives: The present study was designed to explore the effect of duloxetine on experimentally induced pain and inflammation in animal models.
Materials and Methods: The albino Wistar rats of either sex were randomly divided into four groups, i.e., control and ibuprofen, duloxetine (5 mg and 10 mg/kg), with six animals in each group. Analgesia was assessed by hot plate method in rats. Paw edema model in rats after induction with 0.1 mL of 1% carrageenan was used to assess the anti-inflammatory activity. Chronic anti-inflammatory activity was assessed by cotton pellet-induced granuloma. The results obtained were analyzed by analysis of variance followed by Tukey’s Honest sigfnificance difference post-hoc test.
Results: There was a statistically significant increase in reaction time at all time points compared to control in all treatment groups (ibuprofen and duloxetine) in the hot plate methods. Duloxetine (10 mg/kg) is superior to ibuprofen at every time point as shown by increase in mean reaction time. Duloxetine has also shown significant anti-inflammatory effects compared to control. Ibuprofen was found to cause statistically significant decrease in paw size compared to both control and duloxetine in carrageenan-induced rat paw edema. The antiinflammatory effect of duloxetine was not significant compared to ibuprofen as seen in cotton pellet-induced granuloma. Conclusion: The present study showed analgesic and anti-inflammatory effect of duloxetine in dose-dependent matter. Thus, duloxetine may fit to be an agent offering analgesic and anti-inflammatory along with its antidepressant activity