Postoperative pharmacodynamic interaction of ondansetron; a 5-HT3 antagonist and paracetamol in patients operated in the ENT department under local anesthesia.

Vol. 5 | Issue 3 | June-August 2014  84  Preclinical studies in incision pain models and healthy volunteers have demonstrated the central serotonergic analgesic mechanism of paracetamol.[1] This has been supported by some studies with evidence of raising serotonin concentrations in the brain following paracetamol administration.[2] Inhibition of this analgesia by ondansetron/tropisetron; the 5‐HT3 antagonists suggest that this analgesia is 5‐HT3‐mediated.[3] However, in a few studies, these 5‐HT3 antagonists themselves were found to have analgesic action.[4] These drugs are frequently co‐administered, especially in cancer and postoperative patients. Hence, in this study, we have studied the pharmacodynamic interaction between paracetamol and ondansetron with reference to following parameters: