<i>OPRM1</i> and <i>COMT</i> Polymorphisms: Implications on Postoperative Acute, Chronic and Experimental Pain After Cardiac Surgery

Abstract

<b>Aim:</b> Investigate the potential role of <i>OPRM1</i> (mu-opioid receptor) and <i>COMT</i> (catechol-O-methyltransferase enzyme) polymorphisms in postoperative acute, chronic and experimental thermal pain. <b>Methods:</b> A secondary analysis of 125 adult cardiac surgery patients that were randomized between fentanyl and remifentanil during surgery and genotyped. <b>Results:</b> Patients in the fentanyl group with the <i>COMT</i> high-pain sensitivity haplotype required less postoperative morphine compared with the average-pain sensitivity haplotype (19.4 [16.5; 23.0] vs 34.6 [26.2; 41.4]; p = 0.00768), but not to the low-pain sensitivity group (30.1 [19.1; 37.7]; p = 0.13). No association was found between <i>COMT</i> haplotype and other pain outcomes or <i>OPRM1</i> polymorphisms and the different pain modalities. <b>Conclusion:</b><i>COMT</i> haplotype appears to explain part of the variability in acute postoperative pain in adult cardiac surgery patients.