CYP2D6 Phenotype Implications and Clinical Interpretation Recommendation
Poor Metabolizer (e.g.,*4|*4, *3|*6)
CYP2D6 PMs may experience reduced analgesic effects from certain opioids (e.g., codeine, tramadol, oxycodone, hydrocodone) due to reduced production of the active metabolites.
Select alternate or monitor closely for symptoms of insufficient pain relief.
Intermediate Metabolizer (e.g., *9|*40, *2|*4) CYP2D6 IMs may experience reduced analgesic effects from certain opioids (e.g., codeine, tramadol, oxycodone, hydrocodone) due to reduced production of the active metabolites. Select alternate drug or monitor closely for symptoms of insufficient pain relief.
Normal (Extensive) Metabolizer (e.g., *2/*2, *1/*41) CYP2D6 NMs will likely experience the desired effects of certain opioids (e.g., codeine, tramadol, oxycodone, hydrocodone) due to normal formation of the active metabolites. Continue to follow label recommended dosing.
Ultra-Rapid Metabolizer (e.g., *2|*2 XN, *1|*1 XN) CYP2D6 UMs may experience enhanced analgesic effects from certain opioids (e.g., codeine, tramadol, oxycodone, hydrocodone) and an increased risk for toxicities due to increased production of the active metabolites. Select alternate drug or monitor closely for adverse drug events (e.g., nausea, vomiting, constipation, respiratory depression, confusion, urinary retention).