Evaluation of Pharmacogenetic Factors Affecting Fentanyl Requirements for Postoperative Pain Control

Evaluation of Pharmacogenetic Factors Contributing to Dose Requirement of Fentanyl for Postoperative Pain Control: Genetic Polymorphisms of OPRM1, ABCB1, CYP3A4 and CYP3A5

Fentanyl is a widely used opioid analgesic. There are big interindividual variabilities in dose requirements of fentanyl for postoperative pain control. This study aims to reveal the genetic factors affecting the variable requirements of fentanyl during postoperative period.

The candidate genes are OPRM1, ABCB1,CYP3A4 and CYP3A5.

Inclusion Criteria:

• Patients undergoing total abdominal hysterectomy (TAH) or laparoscopy assisted vaginal hysterectomy (LAVH) under general anesthesia
• Patients who want to use intravenous patient controlled analgesia (PCA) after surgery
• ASA physical status class I, II

Exclusion Criteria:

• history of drug addiction
• opioid medication within 12 hours before surgery
• previous history of opioid medication for 3 months
• neurologic disorder
• cardiac disorder
• hepatic disease
• renal disease
• respiratory disease such as COPD, asthma
• sleep apnea
• BMI > 30
• psycotic disorder