A randomized controlled trial comparing tapentadol with oxycodone in non-breastfeeding women post elective cesarean section

Abstract

Background: Tapentadol may allow greater pain relief with reduced “opioid load” compared to oxycodone. Its use has not been studied in the obstetric population. The objective of this study was to compare the efficacy and side effect profile of tapentadol with oxycodone in patients who received spinal anesthesia for elective cesarean section. The trial was registered with EU Clinical Trials Register with CT number 2016-001621-33.

Methods: This was a multicenter, randomized controlled trial. Randomized patients (n = 68) received either 50 mg tapentadol or oxycodone 10 mg 12 hourly postoperatively. The primary endpoint was the sum of pain intensity difference over the first 48 hours of treatment (SPID₄₈). Secondary outcomes included time to rescue medications, SPID₃₆, total pain relief (TOTPAR) scores, patient satisfaction scores, sum of total pain relief and pain intensity difference (SPRID) scores, time to rescue medications and side effects experienced. An analysis of covariance model with baseline pain intensity score as a covariate was used for statistical analysis.

Results: There was no significant difference in the primary endpoint of SPID₄₈ with adjusted mean difference -11.45 (95% CI -35.35, 12.45) p = .34). Oxycodone showed significantly greater SPID₃₆ scores compared to tapentadol with increased time to rescue medication. Side effects experienced were similar between groups.

Conclusion: Tapentadol did not provide superior pain control or improved tolerability compared to oxycodone post cesarean section. Results should be interpreted however with consideration of administration of intrathecal opioids to all patients in this study and debate over the optimal dose of tapentadol for acute pain.

Trial registration: EU Clinical Trials Register identifier: 2016-001621-33.

Keywords:

• Cesarean section
• postoperative pain
• tapentadol
• oxycodone
• opioid side effects
• intrathecal morphine

Transparency

Declaration of funding

Grunenthal Pharma Ltd provided financial support for initial independent statistical analysis for power calculations for this study. Results analysis was performed by the primary author.

Author contributions: R.F.O.C. and S.I. were involved in the trial conception and design. Statistical analysis of results was performed by R.F.O.C. All authors were involved in data collection, drafting and finalizing of paper. All authors agree to be accountable for all aspects of the work.

Declaration of financial/other relationships

R.F.O.C., H.S., S.D., J.C., J.M., N.A., M.M., T.R. and S.I. have disclosed that they have no significant relationships with or financial interests in any commercial companies related to this study or article.

A CMRO peer reviewer on this manuscript is a member of the advisory board for tapentadol and their institution receives funding from the manufacturer of tapentadol.

Acknowledgements

The authors would like to acknowledge Niamh Molloy, Pain Specialist Nurse, the staff of University Hospital Waterford and St Luke’s General Hospital Kilkenny and all the participants of our study.