ABSTRACT
Background: Levocetirizine, the R-enantiomer of Cetirizine has pharmacokinetically and pharmacodynamically favourable characteristics, with rapid onset of action, high bioavailability, high affinity for and occupancy of the H1-receptor, limited distribution, minimal hepatic metabolism together with minimal side effects. Non-steroidal anti-inflammatory drugs (NSAIDs) have been used for many years for analgesic, anti-inflammatory, and more recently in the case of aspirin, antithrombotic purposes. Because of the significant side effect profiles of steroidal and NSAID medications, there is a greater interest in newer compounds such as antihistaminic drugs. This article will consider the potential or otherwise of the reported analgesic and anti-inflammatory effects of levocetirizine to enhance its effectiveness in the treatment of allergic disease with pain.Methods: Albino Wistar rats of either sex weighing 150-250 grams were used. For both Analgesic activity and Anti-inflammatory activity, 4 groups consisting of 6 animals per group were used. Group I: Control: 1% Gum acacia. 2ml/kg, Group II: Standard drug: Diclofenac sodium 4.5mg/kg; Group III: Test Drug 1: Levocetirizine 1mg/kg; Group IV: Test Drugs 2: Levocetirizine 1mg/kg+Diclofenac sodium 4.5mg/kg. Drugs were administered orally. For analgesic activity, Tail clip method and Hot plate method was used. For acute anti-inflammatory activity Carrageenan induced rat paw oedema method was used.Results: Levocetirizine, is found to have significant analgesic activity in rats (1 mg/kg dose) alone and in combination with Diclofenac Sodium in Haffner’s Tail Clip method and Eddy’s Hot Plate Method. Levocetirizine also has got prominent anti-inflammatory activity in acute models evidenced by percentage inhibition of acute rat paw oedema.Conclusions: Levocetirizine possess analgesic and acute anti-inflammatory activity alone and in combination with Diclofenac sodium.