TABLE 3.
TRAMADOL THERAPY RECOMMENDATIONS BASED ON CYP2D6 PHENOTYPE
| Phenotype | Activity score | Implications | Recommendations | Classification of recommendationa |
|---|---|---|---|---|
| CYP2D6 ultrarapid metabolizer | > 2.25 | Increased formation of O-desmethyltramadol (active metabolite) leading to higher risk of toxicity | Avoid tramadol use because of potential for toxicity. If opioid use is warranted, consider a non-codeine opioid. | Strong |
| CYP2D6 normal metabolizer | 1.25≤x≤2.25 | Expected O-desmethyltramadol (active metabolite) formation | Use tramadol label recommended age- or weight-specific dosing. | Strong |
| CYP2D6 intermediate metabolizer | 0<x<1.25 | Reduced O-desmethyltramadol (active metabolite) formation | Use tramadol label recommended age- or weight-specific dosing. If no response and opioid use is warranted, consider non-codeine opioid. | Optional |
| CYP2D6 poor metabolizer | 0 | Greatly reduced O-desmethyltramadol (active metabolite) formation leading to diminished analgesia. | Avoid tramadol use because of possibility of diminished analgesia. If opioid use is warranted, consider a non-codeine opioid. | Strong |
| CYP2D6 indeterminate | n/a | n/a | No recommendation | No recommendation |
a
Rating scheme described in the Supplement.