Mu-Opioid Receptor Genetic Polymorphism and Intrathecal Analgesia
Public ClinicalTrials.gov record NCT00418015. 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.
Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.
Official title
Mu-Opioid Receptor Genetic Polymorphism and the Duration of Intrathecal Fentanyl Labor Analgesia. Mu-Opioid Receptor Genetic Polymorphism and the Efficacy of Postoperative Intrathecal Morphine Analgesia
Brief summary
Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.
Pharmacogenetics has allowed clinicians to identify associations between an individual's genetic profile and his/her response to drugs. The A118G (c.188A\>G)is a single nucleotide polymorphism (SNP) of the mu-opioid receptor (OPRM1). The mutated protein, N40D, appears to increase the binding affinity and potency of beta-endorphin approximately 3-fold. Individuals carrying the variant receptor gene (A118G) may show differences in some of the functions mediated by beta-endorphin action at the altered OPRM1. Combined spinal-epidural (CSE) analgesia is a commonly utilized technique for labor analgesia. Analgesia is initiated with the intrathecal administration of a lipid-soluble opioid (e.g. fentanyl), sometimes combined with a local anesthetic. The mean (± SD) duration of analgesia after intrathecal fentanyl 25 microgram was 89 ± 43 min. The ED50 of intrathecal fentanyl for labor analgesia varies between 14 microgram to 18.2 microgram. The wide variability in the duration of analgesia, as was well the differences in ED50 may result from differences known to affect labor pain (e.g., ethnicity, parity, stage of labor). Another possible explanation for the differences in opioid requirements and duration, as well as incidence of side effects such as itching and nausea/vomiting, is that opioid responsiveness is determined by genetic variability of the µ-opioid receptor. The ED50 for intrathecal fentanyl labor analgesia was significantly lower for parturients carrying the A118G variant of the mu-opioid receptor, compared to parturients with the A118 wild type receptor. The purpose of this study is to determine whether polymorphism at nucleotide 118 of OPRM1 influences the duration of intrathecal opioid (fentanyl) labor analgesia, and intrathecal opioid (morphine) postoperative analgesia.
Study identification
- NCT ID
- NCT00418015
- Recruitment status
- Completed
- Study type
- Observational
- Phase
- Not listed
- Enrollment
- 293 participants
Conditions and interventions
Conditions
Eligibility (public fields only)
- Age range
- 18 Years to 55 Years
- Sex
- Female
- Healthy volunteers
- Accepts healthy volunteers
This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.
Study timeline
- Start date
- Sep 30, 2005
- Primary completion
- Apr 30, 2007
- Completion
- May 31, 2007
- Last update posted
- Apr 13, 2014
2005 – 2007
United States locations
- U.S. sites
- 1
- U.S. states
- 1
- U.S. cities
- 1
| Facility | City | State | ZIP | Site status |
|---|---|---|---|---|
| Northwestern University | Chicago | Illinois | 60611 | — |
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 NCT00418015, 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 Apr 13, 2014 · Synced Sep 2, 2026
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Open the official record
The complete protocol, eligibility criteria, and contact information for NCT00418015 live on ClinicalTrials.gov.