The goal of using parecoxib, an intravenous cyclooxygenase-2 inhibitor as a non-opioid analgesic in the multimodal pain management protocol is to reduce the incidence of opioid-related adverse events, including nausea and vomiting, dizziness, pruritus, constipation, urinary retention, sedation, impaired cognition, respiratory depression and possible death29. This evidence concerns the gene PTGS2 and respiratory depression.