Impact of CYP3A4*1G Polymorphism on Metabolism of Fentanyl in Chinese Patients Undergoing Lower Abdominal Surgery

Study Overview
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Brief Summary
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Purpose: This study aimed to investigate the impact of CYP3A4*1G genetic polymorphism on metabolism of fentanyl in Chinese patients undergoing lower abdominal surgery. Methods: 176 patients receiving elective lower abdominal surgery under general anesthesia were recruited into this study. Genotyping of CYP3A4*1G was carried out by direct sequencing. The plasma fentanyl concentration was detected 30 min after anesthesia induction by high performance liquid chromatography-ultraviolet ray (HPLC-UV). The visual analog scale (VAS) was used for pain evaluation at rest during patient-controlled analgesia (PCA) treatment 0 h, 12 h and 24 h after operation. PCA fentanyl consumption and adverse effects were recorded during the first 24 h after surgery.

Official Title
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Impact of CYP3A4*1G Polymorphism on Metabolism of Fentanyl in Chinese Patients Undergoing Lower Abdominal Surgery

Conditions
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Pain, Surgery

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Aged 20-65 years Anesthesiologists (ASA) physical status I or II; With ±20% of ideal body weight; Received PCA administration; Agreed to participate the research Exclusion Criteria: History of chronic pain; Psychiatric diseases; Diabetes mellitus; Severe cardiovascular diseases; Kidney or liver diseases; Alcohol or drug abuse (according to the criteria of DSM-IV); Pregnancy or at lactation period; Consumed drugs (1week) or foods (3 days) known to inhibit or induce the expression of CYP3A4 enzymes prior to surgery; Refused PCA administration; Disagree to participate to the research

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| *1/*1<br>Grouped by CYP3A4*1G polymorphism, wild-type homozygote | |
| *1/*1G<br>Grouped by CYP3A4*1G polymorphism,*1/*1G: mutant heterozygote | |
| *1G/*1G<br>Grouped by CYP3A4*1G polymorphism,*1G/*1G: mutant homozygote | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| CYP3A4*1G Polymorphism | According to CYP3A4*1G polymorphism,patients are devided into three groups: *1/*1,*1/*1G,*1G/*1G | 48 hours after operation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The Visual Analog Scale 24 Hours Postoperative | The visual analog scale (VAS) is used for pain evaluation at rest which from 0 to 10 (higher values represent morepain) during patient-controlled analgesia (PCA) treatment 24 h after operation | 24 hours after operation | 
| PCA Fentanyl Consumption | PCA fentanyl consumption and adverse effects are recorded during the first 24 h after surgery. | 24 h after surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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gene polymorphism, CYP3A4, fentanyl, HPLC, Analgesics