CYP2D6 drug-gene and drug-drug-gene interactions among patients prescribed pharmacogenetically actionable opioids.

PURPOSE: When codeine and tramadol are used for pain management, it is imperative that nurses are able to assess for potential drug-gene and drug-drug-gene interactions that could adversely impact drug metabolism and ultimately pain relief. Both drugs are metabolized through the CYP2D6 metabolic pathway which can be affected by medications as well the patient's own pharmacogenotype. The purpose of this brief report is to identify drug-gene and drug-drug-gene interactions in 30 adult patients prescribed codeine or tramadol for pain.

METHODS: We used three data sources: (1) six months of electronic health record data on the number and types of medications prescribed to each patient; (2) each patient's CYP2D6 pharmacogenotype, and (3) published data on known CYP2D6 gene-drug and drug-drug-gene interactions.

RESULTS: Ten patients (33%) had possible drug-gene or drug-drug-gene interactions. Five patients had CYP2D6 drug-gene interactions indicating they were not good candidates for codeine or tramadol. In addition, five patients had potential CYP2D6 drug-drug-gene interactions with either codeine or tramadol.

CONCLUSION: Our findings from this exploratory study underscores the importance of assessing and accounting for drug-gene and drug-drug-gene interactions in patients prescribed codeine or tramadol.