Genetic Predictors of Analgesic Efficacy of Propranolol for Treating Postoperative Pain

Contribution of COMT Haplotypes in Propranolol Analgesic Efficacy for Treating Post-surgical Pain After Laparoscopic Hemicolectomy

This study is a randomized, double-blind, placebo controlled clinical trial. The main purpose of this study is to determine if postsurgical pain ratings are improved with treatment with oral Propranolol, and if the effectiveness of treatment can be modified by the presence or absence of SNPs (Single Nucleotide Polymorphism) associated with Cathecol-O-MethylTransferase (COMT) and mu-opioid receptor (MOR1) activity. The treatment period will last for three days and the observation period will last for six months. Effectiveness of treatment will be assessed by means of morphine consumption through quantitative evaluation of IV-PCA (Patient Controlled Analgesia) morphine as primary outcome measure.

Inclusion Criteria:

• Elective laparoscopic hemicolectomy surgery.
• Self-reported Caucasians.
• ASA (American Society of Anesthesiologists) physical status of I or II.
• Agrees to provide signed and dated informed consent form.
• Willingness to agree with the Biobanking policy.

Exclusion Criteria:

• Uncontrolled medical or psychiatric conditions.
• Severe mental impairment.
• History of major depressive disorder, psychotic disorder or schizophrenia, and/or manic episodes within the past year.
• Active alcoholism within the past 6 months.
• Psychoactive recreational drug abuse within the past 6 months including MDMA, Ketamine, hallucinogens such as LSD and/or sympathomimetics such as Cocaine.
• Inability to comprehend pain assessment.
• Pregnancy and/or breast-feeding.
• Known hypersensitivity to Beta Blockers or Opioids.
• Currently taking Propranolol.
• Currently taking other hypotensive treatments.
• Currently taking Opioids.
• Patients with asthma or reactive airway disease.
• Patients with cardiac arrhythmia, coronary artery disease, congestive heart failure.
• Patients with renal failure or dialysis.
• Patients with liver insufficiency.
• Heart rate less than 60bpm or diastolic blood pressure <50 mmHg during the preoperative visit.