Opioid-sparing analgesia with clonidine versus fentanyl in inguinal hernia repair: a randomized clinical trial.

purposeTo evaluate the efficacy, safety, and cost of clonidine compared with fentanyl as an adjuvant for analgesia in patients undergoing inguinal hernia repair.

methodsThis randomized superiority trial included 138 patients allocated to fentanyl (GLF) or clonidine (GLC) groups (n = 69 each), undergoing inguinal hernioplasty under local anesthesia with sedation. The primary outcome was postoperative pain intensity assessed by the visual analog scale (VAS). Secondary outcomes included time to first analgesic request, need for rescue analgesia, sedation level (RASS), adverse events, and medication costs. Results were expressed as mean or median differences, or relative risks, with 95% CI.

resultsBaseline characteristics were comparable between groups. Clonidine significantly reduced pain intensity compared with fentanyl (median 0 [IQR 0-3] vs. median 2 [IQR 0-4]; Mann-Whitney U = 1864; 95% CI of median difference - 3.00 to - 2.00; p = 0.019). The clonidine group also showed greater sedation (mean difference - 0.6; p = 0.009), longer pain-free time (mean difference 2.0 h; p = 0.001), and lower need for rescue analgesia (34.8% vs. 59.4%; RR 0.59; p = 0.006). Adverse events and costs were similar. The reduced need for rescue analgesia suggests a clinically relevant opioid-sparing effect.

conclusionClonidine was superior to fentanyl in improving postoperative analgesia, prolonging pain-free duration, and reducing additional analgesic requirements, while maintaining a comparable safety profile and cost.