Postoperative analgesic effect of nefopam monotherapy and nefopam-fentanyl polytherapy in patients underwent laparoscopic cholecystectomy

Background and Objectives: We investigated the non-inferiority of patient-controlled analgesia (PCA), using either nefopam alone or combined nefopam-fentanyl for postoperative analgesia in patients undergoing laparoscopic cholecystectomy. Materials and Methods: In this prospective, randomized, controlled study, 78 patients were allocated to receive nefopam 240 mg (Group N240) or nefopam 120 mg with fentanyl 600 µg (Group NF), equivalent to fentanyl 1200 µg, with a total PCA volume of 120 mL. Patients were given a loading dose (0.1 mL/kg) from the PCA device along with ramosetron (0.3 mg) and connected to a PCA device with a background infusion rate of 2 mL/h, bolus dose amount set at 2 mL, and lockout interval set at 15 min. Pain scores were obtained using the numeric rating scale (NRS) at 30 min after recovery room (RR) admission, as well as 8 and 24 h postoperatively. The primary outcome was analgesic efficacy evaluated using NRS-rated 8 h postoperatively. Other evaluated outcomes included the incidence rate of bolus demand, rescue analgesic and antiemetic requirements, and postoperative adverse effects. Results: NRS scores were not significantly different between the groups throughout the postoperative period (p = 0.539). NRS scores of group N240 were not inferior to those of group NF at 30 min after RR admission, or at 8 and 24 h postoperatively (mean difference [95% CI], -0.05 [-0.73 to 0.63], 0.10 [-0.29 to 0.50], and 0.28 [-0.06 to 0.62], respectively). Postoperative adverse effects were not significantly different between the two groups (p = 1.000) and other outcomes were also not significantly different between the two groups (p = 0.225). Conclusions: PCA using nefopam alone has a non-inferior and effective analgesic efficacy and produces a lower incidence of postoperative adverse effects compared to a combination of fentanyl and nefopam after laparoscopic cholecystectomy.