Drug interaction checker
107 oncology products and 46 common co-medications with their CYP, P-gp, QT and absorption properties, plus 70 interactions named in labels. Pick two or more and the rules flag every pair: a TKI with an azole, a PPI with an acid-dependent drug, two QT-prolonging agents, warfarin with a fluoropyrimidine. Frequent, avoidable errors, caught before the prescription.
How flags are derived
Each drug carries properties from its prescribing information: CYP3A4 substrate (sensitive or moderate), inhibitor or inducer strength, CYP2D6, CYP2C8 and CYP1A2 roles, QT risk, acid-dependent absorption, P-gp, anticoagulant or bleeding risk. Rules combine them in both directions: sensitive substrate plus strong inhibitor is major, moderate combinations are moderate, two known-risk QT drugs are major. Interactions the label names explicitly (brentuximab with bleomycin, capecitabine with warfarin, high-dose methotrexate with NSAIDs) are added as label pairs. Management text is the victim drug’s own label instruction where one exists.
Limits
This is a decision aid over a curated list, not a complete interaction database: a drug absent from the list is not cleared, and a pair with no flag is not proven safe. CYP classifications follow the FDA interaction tables; QT risk follows the label or CredibleMeds. Checkpoint inhibitors and most antibodies have no pharmacokinetic interactions and are listed for their toxicity notes only; see the irAE guide. Verify in the current label and with a pharmacist. Not medical advice.