Example · Antiplatelet therapyClopidogrel — CYP2C19 *2/*17
Cardiovascular · CPIC Level 1A
- Gene
- CYP2C19
- Diplotype
- *2/*17 — Intermediate metabolizer
- PharmGKB annotation
- Level 1A
- CPIC guideline
- Avoid clopidogrel; use alternative antiplatelet (prasugrel, ticagrelor) for ACS / PCI
- Clinical impact
- Reduced platelet inhibition, elevated cardiovascular event risk
- Population frequency
- ≈30% intermediate metabolizers (European descent)
CYP2C19 governs the conversion of clopidogrel to its active thiol metabolite. Atlas Pharmacogenomics flags intermediate and poor metabolizers as severe and surfaces the alternative therapies in the clinical recommendations section.
Example · Pain managementCodeine — CYP2D6 (variant detected, activity score 0.25–1)
Analgesia · CPIC Level 1A
- Gene
- CYP2D6
- Phenotype
- Reduced metabolizer
- Clinical impact
- Reduced morphine conversion, diminished analgesia at standard doses
- CPIC guideline
- Use alternative non-codeine opioid for pain management; tramadol also affected
- Patient context
- Surgical pain, post-operative analgesia, chronic pain protocols
CYP2D6 is the primary route of conversion from codeine to morphine. Atlas Pharmacogenomics reports the predicted phenotype, the underlying star alleles, and the guideline-level recommendation in plain clinical language so the prescribing decision stays with the physician.
Example · Endocrine cancer therapyTamoxifen — CYP2D6
Oncology · CPIC Level 1A
- Gene
- CYP2D6
- Phenotype
- Reduced metabolizer
- Clinical impact
- Lower endoxifen formation, increased recurrence risk and reduced event-free survival in adjuvant therapy
- CPIC guideline
- Consider alternative hormone therapy (aromatase inhibitor) for postmenopausal patients
- Note
- Genotype-guided therapy increasingly recommended in estrogen-receptor-positive breast cancer
Endoxifen is the principal active metabolite of tamoxifen and depends on CYP2D6 activity. Atlas Pharmacogenomics pairs the genotype with concrete co-medication warnings (strong CYP2D6 inhibitors should be avoided) so this nuance reaches the prescriber.