Effect of Mu-opioid Receptor Genetics on 3 Doses of Spinal Morphine for Postoperative Analgesia After Cesarean Section
Public ClinicalTrials.gov record NCT01465191. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.
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Official title
Effect of OPRM1 Genotype on the Dose Response to Spinal Morphine for Post-Cesarean Analgesia
Brief summary
Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.
HYPOTHESIS: The response to a given dose of morphine given via a spinal anesthetic for cesarean section will be affected by the genetics of the woman's mu-opioid receptor Most women undergoing elective cesarean section (CS) receive spinal anesthesia, and most receive a dose of preservative free morphine with the spinal anesthetic. Spinally-administered morphine provides 16-24 hours of high quality pain relief. The dose administered is usually 75-200 micrograms, but surprisingly few dose-response studies exist. The mu-opioid receptor (OPRM1 gene)is the site of action of endogenous opioid peptides and opioid analgesic drugs like morphine. There is a common genetic variant of this receptor at the 40th amino acid of the protein, with asparagine and asparate being present in different people. The less common variant (aspartate), present in 25-30% of the overall American population (higher in Asian populations, lower in Blacks) at codon 40 that has been shown in many studies to affect opioid analgesia. This will be a randomized, blinded study of 3 doses of spinal morphine (50, 100, 150 micrograms) given to women undergoing elective cesarean section at term pregnancy. 300 women will be studied (100 per dose). Blood will be obtained for genotyping of OPRM1 and other genes that may affect pain and analgesic responses. The primary outcome will be the amount of intravenous morphine patients self-administer in the 24 hours postsurgery. The primary outcome (use of intravenous morphine) will be analyzed by dose, and within each dose group by genotype of OPRM1. Secondary outcomes will include pain scores every 6 hours, satisfaction with analgesia, side effects (itching, nausea/vomiting) by dose and genotype. It is anticipated that there will be an interim data analysis at 150 evaluable subjects for assessment of the dose response to morphine in the overall population; then a final analysis at 300 subjects for the genetic effect assessment.
Study identification
- NCT ID
- NCT01465191
- Recruitment status
- Completed
- Study type
- Interventional
- Phase
- Phase 4
- Enrollment
- 169 participants
Conditions and interventions
Conditions
Eligibility (public fields only)
- Age range
- 18 Years to 45 Years
- Sex
- Female
- Healthy volunteers
- Healthy volunteers not accepted
This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.
Study timeline
- Start date
- Oct 31, 2011
- Primary completion
- Apr 30, 2014
- Completion
- Apr 30, 2014
- Last update posted
- Dec 9, 2020
2011 – 2014
United States locations
- U.S. sites
- 2
- U.S. states
- 2
- U.S. cities
- 2
| Facility | City | State | ZIP | Site status |
|---|---|---|---|---|
| George Washington University Medical Center | Washington D.C. | District of Columbia | 20037 | — |
| Columbia University Medical Center | New York | New York | 10032 | — |
Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.
About this trial record page
- What this page shows
- Public field values for ClinicalTrials.gov record NCT01465191, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
- What this page does not do
- No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
- Where the data comes from
- Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
- Last refresh
- Last update posted Dec 9, 2020 · Synced Sep 8, 2026
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Open the official record
The complete protocol, eligibility criteria, and contact information for NCT01465191 live on ClinicalTrials.gov.