In methadone-treated OD AAs, we identified a single genome-wide significant association with methadone dosing needs, and found that the closest gene was OPRM1. We validated the genetic marker in an independent sample of AA surgical patients receiving morphine for analgesia. Consistent with the observation that this SNP’s influence is evident across different clinical settings where μ-opioid receptor agonism is employed, top SNPs from prior opioid analgesic dose studies were collectively associated with methadone dose in OD patients. The observed effect of the rs73568641 minor allele on methadone dose requirements could have immediate clinical utility in the therapeutic dosing of methadone, and perhaps other μ-opioid receptor agonists, in AA patients. Prospective replication and further clinical characterization in new samples are needed to realize this potential.
