Open clinical references · CPIC-aligned
Pharmacogenomics for oncology
The gene-drug pairs that change oncology dosing or contraindicate a treatment outright. CPIC Level A guidelines — peer-reviewed, regularly updated, free.
Free. No signup. Decision-support aid only — not a substitute for clinical pharmacology consultation.
- CPIC AFluoropyrimidines
DPYD + 5-fluorouracil / capecitabine
DPYD-deficient patients face severe 5-FU toxicity. CPIC Level A, multiple actionable variants (*2A, *13, c.2846A>T, HapB3).
Open reference →
- CPIC AFluoropyrimidines
DPYD + capecitabine (oncology focus)
Same DPYD biology, capecitabine-specific dosing considerations. Pre-treatment genotyping reduces grade 3-4 toxicity.
Open reference →
- CPIC ATopoisomerase I inhibitor
UGT1A1 + irinotecan
UGT1A1*28 and *6 reduce SN-38 glucuronidation. Severe neutropenia and diarrhea risk; dose-reduction by genotype.
Open reference →
- CPIC AThiopurines
TPMT + thiopurines (AML, ALL, IBD)
TPMT poor metabolizers face fatal myelosuppression on standard 6-MP / azathioprine doses. Pre-treatment genotyping mandatory.
Open reference →
- CPIC AAntiplatelet
CYP2C19 + clopidogrel
CYP2C19 *2 / *3 poor metabolizers — clopidogrel underactivation. Relevant to oncology patients on anticoagulation.
Open reference →
- CPIC ASERM
CYP2D6 + tamoxifen
CYP2D6 poor metabolizers may have reduced endoxifen exposure. Controversial benefit; some guidelines recommend testing.
Open reference →
Related references
Looking for somatic variant evidence? See the variant cheat sheets. Looking for active trials by gene? See the trial-by-gene index.
CPIC = Clinical Pharmacogenetics Implementation Consortium. Guidelines are peer-reviewed and freely available at cpicpgx.org.