Investigating the Role of Ultra-Low Dose Naloxone in Modulating Postoperative Pain after Laparoscopic Cholecystectomy: A Double-Blind Randomized Controlled Trial

Background: Considering the importance of controlling post-surgical pain in individuals and the limitation in number, in addition to the variations in the results of the clinical research studies focused on pain management outcomes of very low dose naloxone, the present evaluation aims to investigate the role of ultra-low dose naloxone on the severity of pain after the procedure, nausea, vomiting and pruritic. Methods: In this double-blind controlled randomized clinical trial, 60 patients were selected for laparoscopic cholecystectomy surgery, with class 1 and 2 anesthesia (ASA) by available method, and were allocated to the intervention and control groups using randomization. Every participant underwent general anesthesia with a specific anesthesia protocol. After the operation, PCA was implanted for all patients to control pain. The internal composition of the PCA pump included 20 mg of morphine and naloxone at a specified dosage of 0.25 μg/kg for the intervention group and 20 mg of morphine and placebo for the control arm. Pain intensity, episodes of nausea and emesis and pruritic of patients were evaluated and compared based on VAS criteria within the two groups being analysed, during the immediate postoperative period and then 2, 6, 12 and 24 hours following the surgical procedure. Results: There was no meaningful variation between therapeutic and standard arms in terms of age, sex, BMI, duration of surgery, duration of anesthesia, and dose of intra-operative fentanyl injection. Also, with respect to the level of pain during the immediate postoperative period and 2, 6, 12, and 24 hours following the surgical procedure, and the intensity of nausea, vomiting, and pruritic during recovery, statistical analysis revealed no remarkable discrepancy between the arms. In both groups, the severity of pain showed a significant decline at each of the examined time points in comparison with the pre-intervention phase (p <0.001, for both groups). Comparing the trend of changes in pain intensity during the postoperative period between the two study groups did not show a statistically meaningful variation (p = 0.569). Conclusion: The simultaneous prescription of naloxone and morphine in patients undergoing laparoscopic cystectomy does not demonstrate a meaningful influence on achieving relief from post-surgical pain levels, nausea and vomiting and pruritic compared to morphine alone, so the use of naloxone to reduce postoperative pain and complications of opioids is not recommended.