مرکز منطقه ای اطلاع رساني علوم و فناوري - Paracetamol and cyclooxygenase enzyme inhibition

Abstract :

Parasetamol has been reliably used for over 100 years as analgesic and antipyretic but its mechanism of action is still not fully understood. Although the cyclooxygenase (COX) enzyme inhibition plays in one of the mechanisms of action of paracetamol, especially the contribution of other mechanisms, such as serotonergic and opioiderjik system is well known for the mechanism of analgesic effect today. By using various animal experimental models and clinical trials, it was reported that the antiinflammatory effect of paracetamol is nearly equivalent the other nonsteroid antiinflammatory drugs’ (NSAID); but due to its lacked effect in the autoinflammatory diseases such as rheumatoid artritis, it was reguired the paracetamol should be saperated from the other NSAIDs’ classification. Paracetamol indirectly inhibits the cyclooxygenase enzyme. This inhibition has been claimed to have disappeared in the presence of relatively high level of peroxide. Although it was shown that the inhibition of cyclooxigenase enzyme causes analgesic and antipyretic effect in central nervous ystem (CNS) that have a low peroxide activity, the lack of effect of paracetanole on the immune cells and trombocytes that have a high peroxide activity has been shown, thefore, it was claimed paracetamole had no effect in the diseases such as rheumatoid artritis which have a high peroxide activity. Since the beginning of 2000, a new COX enzyme variant was developed and it was thought that COX-3 may play a role in the mechanism of action of paracetamol. But in the studies, it is not clearly defined both the specifity of this enzyme and its interaction with the paracetamol. The purpose of this review is to give a knowledge about the effects of paracetamol on COX enzyme inhibition.