Subcutaneous Methadone for Cesarean Analgesia: a Non Inferiority Study Using QoR-10

NCT07777029 | Not Yet Recruiting DMC

• 1 other identifier: alemana
• Study Type: interventional
• Target: 128
• Locations: 0 countries
• Sites: N/A

Brief Summary

This study aims to evaluate whether subcutaneous methadone provides postoperative analgesia that is non-inferior to that achieved with intrathecal morphine in women undergoing cesarean delivery under neuraxial anesthesia. The primary outcome will be the quality of postoperative recovery, assessed using the QoR-10 score during the first 24 hours after surgery. Secondary outcomes will include postoperative pain intensity, opioid consumption, incidence of adverse effects, and maternal satisfaction. This trial seeks to determine whether subcutaneous methadone could represent an alternative analgesic strategy within multimodal analgesia protocols for cesarean delivery.

Conditions

Cesarean Section Pain

Keywords

cesarean section; methadone; intratecal morphine; recovery; maternal satisfaction

Outcome Measures

Primary Outcomes (1)

• Quality of Recovery-10 (QoR-10) score at 24 hours

  cesarean delivery. The QoR-10 is a validated patient-reported outcome measure ranging from 0 to 100, with higher scores indicating better recovery. The study is designed to assess noninferiority of subcutaneous methadone compared to intrathecal morphine using a predefined noninferiority margin of 8 points.

  24 hours

Secondary Outcomes (3)

• Postoperative pain intensity

  Up to 24 hours after surgery

• Opioid consumption

  Up to 24 hours after surgery

• adverse effects

  24 hours

Study Arms (2)

Subcutaneous methadone

EXPERIMENTAL

Patients receive subcutaneous methadone for postoperative analgesia following cesarean delivery under neuraxial anesthesia as part of a multimodal analgesia regimen.

Drug: Methadone 0.15 mg/kg

Intrathecal morphine

ACTIVE COMPARATOR

Patients recieve intrathecal preservative-free morphine for postoperative analgesia following cesarean delivery under neuraxial anesthesia as part of a multimodal analgesia regimen.

Drug: morphine

Interventions

morphine DRUG

Intrathecal morphine administered during neuraxial anesthesia for postoperative analgesia following cesarean delivery.

Intrathecal morphine

Methadone 0.15 mg/kg DRUG

Subcutaneous methadone administered for postoperative analgesia following cesarean delivery under neuraxial anesthesia.

Subcutaneous methadone

Eligibility Criteria

• Age: 18 Years - 45 Years
• Sex: female
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• Women aged 18-45 years
• Singleton pregnancy at term (≥37 weeks of gestation)
• Scheduled for elective cesarean delivery
• Planned neuraxial spinal anesthesia
• Ability to understand and complete the QoR-10 questionnaire
• Provision of written informed consent

You may not qualify if:

• Emergency cesarean delivery
• Contraindication to neuraxial anesthesia
• Known hypersensitivity or allergy to methadone or morphine
• Chronic opioid use or opioid dependence

Sponsors & Collaborators

• Clinica Alemana de Santiago: lead

Related Publications (3)

• Crowe G, Atterton B, Roofthooft E, Joshi GP, Rawal N, Wu C, Sauter AR, Bonnet MP, Lucas DN, Van de Velde M; PROSPECT Working Group of the European Society of Regional Anaesthesia and Pain Therapy. Pain management after elective caesarean section under neuraxial anaesthesia: an updated systematic review and procedure-specific postoperative pain management (PROSPECT) recommendations. Anaesthesia. 2026 Jun;81(6):819-839. doi: 10.1111/anae.70141. Epub 2026 Feb 15.

  PMID: 41693258 BACKGROUND

• Guevara J, Sanchez C, Organista-Montano J, Domingue BW, Guo N, Sultan P. Development and validation of a Spanish version of the Obstetric Quality of Recovery-10 item score (ObsQoR-10-Spanish). BJA Open. 2024 Mar 21;10:100269. doi: 10.1016/j.bjao.2024.100269. eCollection 2024 Jun.

  PMID: 38560622 BACKGROUND

• Russell T, Mitchell C, Paech MJ, Pavy T. Efficacy and safety of intraoperative intravenous methadone during general anaesthesia for caesarean delivery: a retrospective case-control study. Int J Obstet Anesth. 2013 Jan;22(1):47-51. doi: 10.1016/j.ijoa.2012.10.007. Epub 2012 Dec 7.

  PMID: 23219678 BACKGROUND

MeSH Terms

Interventions

Methadone; Morphine

Intervention Hierarchy (Ancestors)

Ketones; Organic Chemicals; Morphine Derivatives; Morphinans; Opiate Alkaloids; Alkaloids; Heterocyclic Compounds; Heterocyclic Compounds, Bridged-Ring; Heterocyclic Compounds, 4 or More Rings; Heterocyclic Compounds, Fused-Ring; Phenanthrenes; Polycyclic Aromatic Hydrocarbons; Polycyclic Compounds

Central Study Contacts

JAVIERA VARGAS, MD, MSc

CONTACT

+56957383772; jpvargasz@gmail.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: A sample size calculation was performed for a non-inferiority study with two parallel groups and 1:1 allocation, using the total Obs-Quality of Recovery-10 score as the primary outcome, analyzed as a continuous variable. The non-inferiority margin was set at 8 points, defined as the maximum clinically acceptable difference to consider the intervention not inferior to the control. The estimation assumed a common standard deviation of 15.2 points, based on preliminary data, a one-sided significance level of 0.025, and 80% statistical power. Under the assumption of no true differences between groups, the calculated sample size was 58 patients per group. Accounting for a 10% rate of loss to follow-up or incomplete data, the final sample size was adjusted to 64 patients per group, for a total of 128 patients.

Study Record Dates

• First Submitted: August 18, 2026
• First Posted: August 20, 2026
• Study Start: August 21, 2026
• Primary Completion (Estimated): December 31, 2026
• Study Completion (Estimated): March 31, 2027
• Last Updated: August 20, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will not share