Implementing Genomics in Practice (IGNITE) Proof of Concept Study: Genotyping in Family Medicine Clinics

Codeine and tramadol are opioid analgesics that depend on cytochrome P450 2D6 (CYP2D6) for bioactivation to morphine and O-desmethyltramadol, respectively. Morphine and O-desmethyltramadol have much greater affinity for the opioid receptor and thus are more powerful analgesics. Individuals with genotypes associated with low CYP2D6 activity (poor metabolizers) are unable to convert sufficient amounts of codeine or tramadol to their active metabolites and may fail to derive sufficient pain relief. At the opposite extreme, individuals with genotypes associated with increased CYP2D6 activity (ultra-rapid metabolizers) are at risk for serious toxicity with usual codeine or tramadol doses. The CYP2D6 genotype also has implications for response to other drugs, such as tricyclic antidepressants (TCAs), which are commonly used for neuropathic pain. Patients will be recruited from family medicine clinics, serving as either implementation sites or control sites. Patients from implementation sites will undergo CYP2D6 genotyping, with results placed in the medical record to assist with prescribing of pain medications. Pain medications prescribed from baseline to 3 months will be assessed through medical record review. A pain assessment questionnaire will be administered to patients enrolled from both sites at baseline and 3 months. At the end of the study, a 20-item survey will be administered to physicians at the implementation sites. We will assess whether having CYP2D6 genotype results is useful to inform prescribing decisions for pain medication from the physician's perspective. We will also assess medicines prescribed to patients enrolled from both sites over the 12-month period after enrollment from medical record review and determine the number of patients who were prescribed a medication that has genetic information in its FDA-approved label.