Pharmacogenomics-guided policy in opioid use disorder (OUD) management: An ethnically-diverse case-based approach

- Buprenorphine is used for opioid use disorder (OUD) management and is metabolized by the cytochrome P450 3A4 (CYP3A4) enzyme
- Pharmacogenomics studies the effect of inherited genetic variation on drug response and can personalize buprenorphine dosing
- Patients carrying the CYP3A4*1B allele may require higher than recommended doses of buprenorphine to optimize OUD management
- Key stakeholders must be consulted when establishing pharmacogenetic testing as the standard of care in OUD management

IntroductionOpioid use disorder (OUD) is characterized by a problematic pattern of opioid use leading to clinically-significant impairment or distress. Opioid agonist treatment is an integral component of OUD management, and buprenorphine is often utilized in OUD management due to strong clinical evidence for efficacy. However, interindividual genetic differences in buprenorphine metabolism may result in variable treatment response, leaving some patients undertreated and at increased risk for relapse. Clinical pharmacogenomics studies the effect that inherited genetic variations have on drug response. Our objective is to demonstrate the impact of pharmacogenetic testing on OUD management outcomes.MethodsWe analyzed a patient who reported discomfort at daily buprenorphine dose of 24 mg, which was a mandated daily maximum by the pharmacy benefits manager. Regular urine screenings were conducted to detect the presence of unauthorized substances, and pharmacogenetic testing was used to determine the appropriate dose of buprenorphine for OUD management.ResultsAt the 24 mg buprenorphine daily dose, the patient had multiple relapses with unauthorized substances. Pharmacogenetic testing revealed that the patient exhibited a cytochrome P450 3A4 ultrarapid metabolizer phenotype, which necessitated a higher than recommended daily dose of buprenorphine (32 mg) for adequate OUD management. The patient exhibited a reduction in the number of relapses on the pharmacogenetic-based dose recommendation compared to standard dosing.ConclusionPharmacogenomic testing as clinical decision support helped to individualize OUD management. Collaboration by key stakeholders is essential to establishing pharmacogenetic testing as standard of care in OUD management.