Gencer M, et al. - In this prospective analysis, the μ-Opioid receptor activity was evaluated preoperatively for its link with postoperative pain level as well as second analgesic need in patients receiving septoplasty. A total of 120 adult patients who had septoplasty from June 2015 to January 2019 participated in this study. These patients were randomly categorized into 2 preoperative groups. Patients in the first group (n = 60) were administered tramadol (1–2 mg/kg) for postoperative pain relief and those in the second group (control group) (n = 60) were initially prescribed only fentanyl (1 μg/ kg-i.v.) in the induction. As an rescue painkiller, acetaminophen with codeine analgesic 325/30 mg (p.o.) was used in the postoperative period. As the levels of μ-Opioid receptors raised in patients who received tramadol, visual analogue scores and second analgesic use reduced in postoperative period. Overall, findings revealed that a higher efficacy of opioid analgesic agents as well as a lesser requirement for additional analgesic agents was observed in patients who exhibited higher μ-Opioid receptor levels.