EVALUATION OF ANALGESIC AND ANTI-INFLAMMATORY ACTIVITY OF CETIRIZINE AND LEVOCETIRIZINE: AN EXPERIMENTAL STUDY

Aim of the study: To evaluate analgesic and anti-inflammatory activities of cetirizine and levocetirizine in different experimental models in rats. Materials and Methods: Analgesic activity of cetirizine and levocetirizine was assessed in tail flick model in rats (n = 6), where it was compared with aspirin and tramadol. Reaction time in seconds was used as the unit for measurement of pain and an increase in reaction time was indicative of analgesia. Anti-inflammatory activity of cetirizine and levocetirizine was evaluated using carrageenan-induced rat paw oedema model for acute inflammation (n=6). Percentage inhibition of oedema was compared in different groups. Formalin-induced arthritis model in rats (n=6) was used to evaluate activity in chronic inflammation, where it was compared with aspirin. Linear cross-section (LCS) immediately below the ankle joint of right hind paw was measured daily with Vernier Calliper. The difference in LCS on day 1 and day 10 was calculated for all groups. Results: Both cetirizine and levocetirizine were found to have significant analgesic action which was comparable to aspirin in tail-flick model of analgesia in rats. The effect of tramadol was significantly more than the other drugs at all observation times. In the models of acute and chronic inflammation, both cetirizine and levocetirizine showed significant anti-inflammatory activity which was comparable to aspirin. Conclusion: Cetirizine and levocetirizine possess analgesic and anti-inflammatory activity, which is comparable to aspirin.