Cesarean Section PainSC-METH-CESNCT07777029
Subcutaneous Methadone for Cesarean Analgesia: a Non Inferiority Study Using QoR-10
A study testing Methadone 0.15 mg/kg and morphine in people with Cesarean Section Pain, run by Clinica Alemana de Santiago.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 to 45 years, women only
- Conditions the study is for
- Cesarean Section Pain
- What is being tested?
- Methadone 0.15 mg/kg and morphine
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 128 participants
- Where
- No sites listed yet
- Study dates
- 21 Aug 2026to 31 Mar 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 45 years
- Women only
- No healthy volunteers
- Adult
Who may be able to join
- 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
Who cannot join
- Emergency cesarean delivery
- Contraindication to neuraxial anesthesia
- Known hypersensitivity or allergy to methadone or morphine
- Chronic opioid use or opioid dependence
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
About this study
Official title: Subcutaneous Methadone for Cesarean Analgesia: A Non-inferiority Study Using Quality of Recovery -10 Score.
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.
Read the detailed description
Effective postoperative analgesia following cesarean delivery is a fundamental component of maternal recovery and patient satisfaction. Current international recommendations, including the most recent 2026 update from the PROSPECT Working Group, emphasize that neuraxial morphine remains the gold standard for postoperative analgesia. These guidelines also highlight the strong evidence supporting multimodal analgesia strategies, including the routine use of paracetamol and dexamethasone as adjuncts to improve analgesic outcomes and postoperative recovery.
Despite its efficacy, intrathecal morphine may be associated with dose-dependent adverse effects, such as pruritus, nausea, vomiting, and respiratory depression. For this reason, there remains ongoing clinical interest in identifying alternative analgesic strategies that provide comparable efficacy with a more favorable safety profile.
Methadone is a long-acting opioid that also exhibits N-methyl-D-aspartate (NMDA) receptor antagonist properties, which may enhance analgesia and reduce postoperative opioid requirements. There is evidence supporting its use in cesarean delivery when administered intravenously. In particular, a randomized trial demonstrated that intravenous methadone provides effective postoperative analgesia following cesarean delivery. However, other routes of administration have not been adequately evaluated in this setting.
The subcutaneous route may offer several potential advantages, including ease of administration, predictable absorption, and sustained systemic drug exposure, which could make it a practical alternative in obstetric analgesia. To date, subcutaneous methadone has not been evaluated nor directly compared with intrathecal morphine, which remains the current standard for post-cesarean analgesia.
- Conditions
- Cesarean Section Pain
- Being tested
- Methadone 0.15 mg/kg, morphine
- Keywords
- cesarean section, methadone, intratecal morphine, recovery, maternal satisfaction
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Methadone 0.15 mg/kgDrug
Subcutaneous methadone administered for postoperative analgesia following cesarean delivery under neuraxial anesthesia.
morphineDrug
Intrathecal morphine administered during neuraxial anesthesia for postoperative analgesia following cesarean delivery.
| Study group | Role | What they receive |
|---|---|---|
| Subcutaneous methadone | Experimental | Patients receive subcutaneous methadone for postoperative analgesia following cesarean delivery under neuraxial anesthesia as part of a multimodal analgesia regimen. Receives: 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. Receives: Drug: morphine |
What is being measured
The primary outcome is the main question the study is designed to answer.
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.
Measured: 24 hours
Secondary outcomes (3)
Postoperative pain intensity
Pain intensity measured using a numerical rating scale (0-10) at rest and during movement.
Measured: Up to 24 hours after surgery
Opioid consumption
Total opioid consumtion within the first 24 hours after cesarean section, converted to morphine oral equivalents
Measured: Up to 24 hours after surgery
adverse effects
incidence of nausea, vomiting, pruritus, somnolence, respiratory deppresion within 24 hours
Measured: 24 hours
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 Aug 2026
- Study start21 Aug 2026 (estimated)
- Primary completion31 Dec 2026 (estimated)
- Study completion31 Mar 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for Cesarean Section PainStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- 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.
- Masking
- Double blind
- Who is masked
- Participant, Outcomes assessor
- Enrolment
- 128 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Clinica Alemana de Santiago
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07777029
- Sponsor's protocol ID
- alemana
- Acronym
- SC-METH-CES
- Status last verified
- Apr 2026
- First submitted
- 18 Aug 2026
- Last updated
- 20 Aug 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: No individual participant data will be shared. The raw data will not be publicly available due to participant privacy and ethical constraints.
Publications
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.
PubMed 41693258Guevara 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.
PubMed 38560622Russell 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.
PubMed 23219678
Study at a glance
From the registry record, last updated by the sponsor on 20 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Subcutaneous Methadone for Cesarean Analgesia: A Non-inferiority Study Using Quality of Recovery -10 Score.
- ClinicalTrials.gov ID
- NCT07777029
- Acronym / sponsor ID
- SC-METH-CES / alemana
- Conditions
- Cesarean Section Pain
- Keywords
- cesarean section, methadone, intratecal morphine, recovery, maternal satisfaction
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 128 participants (estimated)
- Lead sponsor
- Clinica Alemana de SantiagoUniversity, hospital or other
- Study start
- 21 Aug 2026 (estimated)
- Primary completion
- 31 Dec 2026 (estimated)
- Study completion
- 31 Mar 2027 (estimated)
- First posted
- 20 Aug 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
Effective postoperative analgesia following cesarean delivery is a fundamental component of maternal recovery and patient satisfaction. Current international recommendations, including the most recent 2026 update from the PROSPECT Working Group, emphasize that neuraxial morphine remains the gold standard for postoperative analgesia. These guidelines also highlight the strong evidence supporting multimodal analgesia strategies, including the routine use of paracetamol and dexamethasone as adjuncts to improve analgesic outcomes and postoperative recovery.
Despite its efficacy, intrathecal morphine may be associated with dose-dependent adverse effects, such as pruritus, nausea, vomiting, and respiratory depression. For this reason, there remains ongoing clinical interest in identifying alternative analgesic strategies that provide comparable efficacy with a more favorable safety profile.
Methadone is a long-acting opioid that also exhibits N-methyl-D-aspartate (NMDA) receptor antagonist properties, which may enhance analgesia and reduce postoperative opioid requirements. There is evidence supporting its use in cesarean delivery when administered intravenously. In particular, a randomized trial demonstrated that intravenous methadone provides effective postoperative analgesia following cesarean delivery. However, other routes of administration have not been adequately evaluated in this setting.
The subcutaneous route may offer several potential advantages, including ease of administration, predictable absorption, and sustained systemic drug exposure, which could make it a practical alternative in obstetric analgesia. To date, subcutaneous methadone has not been evaluated nor directly compared with intrathecal morphine, which remains the current standard for post-cesarean analgesia.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, outcomes assessor)
- Number of arms
- 2
- Model description
- 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.
| Arm | Type | Receives |
|---|---|---|
| Subcutaneous methadone | Experimental | Drug: Methadone 0.15 mg/kgPatients receive subcutaneous methadone for postoperative analgesia following cesarean delivery under neuraxial anesthesia as part of a multimodal analgesia regimen. |
| Intrathecal morphine | Active comparator | Drug: morphinePatients recieve intrathecal preservative-free morphine for postoperative analgesia following cesarean delivery under neuraxial anesthesia as part of a multimodal analgesia regimen. |
Who may qualify
- Ages
- 18 to 45 years
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (6 listed)
- 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
Key exclusion criteria (4 listed)
- Emergency cesarean delivery
- Contraindication to neuraxial anesthesia
- Known hypersensitivity or allergy to methadone or morphine
- Chronic opioid use or opioid dependence
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Methadone 0.15 mg/kgSubcutaneous methadone administered for postoperative analgesia following cesarean delivery under neuraxial anesthesia. | Drug | Subcutaneous methadone |
| morphineIntrathecal morphine administered during neuraxial anesthesia for postoperative analgesia following cesarean delivery. | Drug | Intrathecal morphine |
Primary outcome
Quality of Recovery-10 (QoR-10) score at 24 hours
Time frame: 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.
3 secondary outcomes
Postoperative pain intensity
Time frame: Up to 24 hours after surgery
Opioid consumption
Time frame: Up to 24 hours after surgery
adverse effects
Time frame: 24 hours
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 20 Aug 2026.
- Background: PubMed 41693258Crowe 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.
- Background: PubMed 38560622Guevara 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.
- Background: PubMed 23219678Russell 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.
- Individual participant dataSharing planned: No. No individual participant data will be shared. The raw data will not be publicly available due to participant privacy and ethical constraints.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Questions about this trial
What is this clinical trial studying?
A study testing Methadone 0.15 mg/kg and morphine in people with Cesarean Section Pain, run by Clinica Alemana de Santiago.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 20 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact JAVIERA VARGAS, MD, MSc (+56957383772, jpvargasz@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Quality of Recovery-10 (QoR-10) score at 24 hours (time frame: 24 hours). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07777029, which also lists 3 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 20 Aug 2026.