Post-cesarean gabapentin is not associated with lower opioid consumption or pain scores in women on chronic buprenorphine therapy: A 10-year retrospective cohort study

Abstract

Study objective: To determine if postoperative gabapentin administration is associated with decreased opioid consumption or pain scores following cesarean delivery in women on chronic buprenorphine.

Design: Retrospective cohort study.

Setting: Postoperative recovery area and postpartum inpatient unit.

Patients: 214 women undergoing cesarean delivery while on chronic buprenorphine at a single institution between 2007 and 2017.

Interventions: Gabapentin treatment for post-cesarean analgesia.

Measurements: The primary outcome was opioid consumption in morphine milligram equivalents, comparing patients who received ≥1 dose of gabapentin within 24 h of cesarean delivery to those who did not. Secondary outcomes included opioid consumption 24-48 and 48-72 h post-cesarean and postoperative numerical rating scale pain scores.

Main results: Of 214 included patients, 64 (30%) received gabapentin while 150 (70%) did not. Gabapentin patients were more likely than controls to have received neuraxial fentanyl (30% vs. 14%, p = 0.01) and transversus abdominis plane block (6% vs. 1%, p = 0.05) and overall received higher doses of ketorolac and acetaminophen. Control patients were more likely to have received neuraxial morphine (78% vs. 90%, p = 0.04) and received higher doses of ibuprofen. In unadjusted analysis, there was no significant difference in morphine milligram equivalent consumption 0-24 h postoperatively between gabapentin (55 mg [IQR 26,84]) and control (53 mg [IQR 28,75]) groups (p = 0.38). After controlling for potential confounders, there remained no significant effect of gabapentin administration (overall effect p = 0.99). Opioid consumption and pain scores were also not significantly different at any other time points.

Conclusions: In parturients receiving chronic buprenorphine, inclusion of gabapentin in a multimodal analgesic regimen was not associated with lower opioid consumption or pain scores during the first 72 h after cesarean delivery. Prospective randomized studies are needed to confirm these findings.

Keywords: Acute pain; Chronic buprenorphine therapy; Gabapentin; Multimodal analgesia; Opioids; Post-cesarean analgesia; Post-cesarean pain.