Perioperative Gabapentin and Opioid Requirements: A Randomized Controlled Trial

IMPORTANCE: Utilizing nonopioid analgesics is critical for postoperative pain control. The exact regimen has not been determined. OBJECTIVE: This study aimed to determine if preoperative gabapentin is noninferior to preoperative and postoperative gabapentin following prolapse surgery. STUDY DESIGN: This was a randomized, double-blinded, placebo-controlled noninferiority trial of patients undergoing prolapse repair. The primary outcome was the percentage of patients requiring an opioid prescription at discharge. Secondary outcomes included pain scores, total morphine milligram equivalents used, postoperative nausea, sedation scores using the Stanford Sleepiness Scale, and frequency of opioid refill requests. The control group received preoperative and postoperative gabapentin. The experimental group received preoperative gabapentin and postoperative placebo. Both groups received acetaminophen and ibuprofen preoperatively and postoperatively, with oxycodone available as needed. Patients who used ≥5 oxycodone doses received a prescription for opioids on discharge. Assuming 23.1% of patients who receive preoperative and postoperative acetaminophen, ibuprofen, and gabapentin require an opioid prescription at discharge and a 20% noninferiority margin, 55 patients per arm were required to achieve a power of 80% with a significance level of 0.05. RESULTS: A total of 114 patients completed participation: 55 in the control group and 59 in the placebo group. The control group did not differ from the experimental group in terms of receiving an opioid prescription at discharge (27.0% vs 32.0%, P=0.57, absolute risk difference: 5.0%; 95% CI, -12%, 21%) or requesting a refill or new prescription for opioids within 6 weeks postoperatively (10.9% vs 15.3%, P=0.49). CONCLUSIONS: We cannot conclude that placebo is noninferior to postoperative gabapentin as a strategy to reduce opioid prescriptions at discharge because the upper margin of the 95% confidence interval exceeded our a priori established 20% margin.