CYP2D6 Polymorphisms and Response to Codeine and Tramadol

CYP2D6 Polymorphisms and Response to Codeine and Tramadol

The science of how an individual’s genotype affects the body’s response to drugs, termed pharmacogenomics, began in the late 1950’s. Since then the promise that medicines could be tailored to the individual instead of the one-size-fits-all approach has been heralded as the future of medicine [1-3]. However, pharmacogenomics has made very little impact on the practice of pain management at the point of care and clinicians still rely on a ‘trial and error’ approach to prescribing and dosing. This carries the risk of adverse events due to toxicity and sub-optimal analgesic response [4-6]. The largest epidemiological study of adults with chronic pain in Europe to date found that 40% of participants reported inadequate pain management by medication and 44% of participants reported that their medications were regularly changed due to lack of efficacy [7]. In 23% of individuals pain was managed by codeine or tramadol. Codeine and tramadol are prodrugs and require biotransformation primarily in the liver to active metabolites for analgesic efficacy [8]. The purpose of this Editorial is to discuss CYP2D6 polymorphisms and codeine non-response in pain populations.