Comparison of the Analgesic, Antipyretic, and Anti-inflammatory Efficiency Between Nimesulide and Aspirin in Mice

Abstract

HE NSAIDs are drugs that differ in their pharmacological efficacy depending on their selectivity against COX2 enzyme. Therefore, the aim of study was to compare the pharmacological effects (analgesic, antipyretic, and anti-inflammatory) between nimesulide (selective) and aspirin (nonselective) COX2 inhibitors in mice. Analgesic ED50s for nimesulide and aspirin were 7.9 and 212.23 mg/kg, respectively. Both drugs exert their effects in a dose-dependent routine. The visceral analgesia (writhing reflex induced by 1% acetic acid) of nimesulide (15.8 mg/kg, i.m.) and aspirin was examined and revealed a significant superiority of nimesulide over aspirin (424.5 mg/kg, i.m) in decreasing the numbers of writhing reflex and percentages of inhibition in writhing numbers to be 66 and 46 %, respectively. The antipyretic effect of nimesulide was significantly more efficient than aspirin through decreasing the fever which induced by baker's yeast (135 mg/kg, i.p.) for overall measured times after injection at 1, 2, 3, and 4h while aspirin has a good and significant antipyretic action after 2h of baker's yeast injection. Formalin (1%) induced inflammation when injected in the paw for the positive (control) group of mice in comparison to the negative (control) group (injected with saline solution) while nimesulide decreased the inflammation in a good manner unlike the aspirin at 0.5, 1, and 2h after formalin injection. Our data demonstrate that nimesulide has better pharmacological properties than aspirin which is related to analgesia, antipyresis, and anti-inflammatory effect in mice which makes it useful for practical use in the field of veterinary medicine.