Drug interactions
Apalutamide + Tucatinib
Severity: Major
Apalutamide and Tucatinib: major interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Apalutamide may decrease tucatinib exposure since tucatinib is metabolized mainly by CYP2C8 with CYP3A contribution. Lower levels may reduce efficacy in HER2-positive cancer.
What this interaction means in plain words
Apalutamide and Tucatinib can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Apalutamide belongs to Endocrine; Tucatinib belongs to Oncology.
Why it happens
Apalutamide induces CYP3A4 and CYP2C8, increasing tucatinib clearance.
What to do
Avoid concurrent use, as tucatinib labeling advises against strong CYP3A or CYP2C8 inducers. Use an alternative antiandrogen if possible.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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Other interactions of Apalutamide
- Apalutamide + Cabotegravir Contraindicated
- Apalutamide + Cobicistat Contraindicated
- Apalutamide + Doravirine Contraindicated
- Apalutamide + Elbasvir / grazoprevir Contraindicated
- Apalutamide + Ensitrelvir Contraindicated
- Apalutamide + Fostemsavir Contraindicated
Other interactions of Tucatinib
- Cisapride + Tucatinib Contraindicated
- Eletriptan + Tucatinib Contraindicated
- Ergotamine + Tucatinib Contraindicated
- Flibanserin + Tucatinib Contraindicated
- Ranolazine + Tucatinib Contraindicated
- Amobarbital + Tucatinib Major
Frequently asked questions
Can I take Apalutamide with Tucatinib?
MediHelp rates the interaction as major. Apalutamide and Tucatinib can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Apalutamide may decrease tucatinib exposure since tucatinib is metabolized mainly by CYP2C8 with CYP3A contribution. Lower levels may reduce efficacy in HER2-positive cancer.
How serious is the interaction between Apalutamide and Tucatinib?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid concurrent use, as tucatinib labeling advises against strong CYP3A or CYP2C8 inducers. Use an alternative antiandrogen if possible.
What other medicines interact with Apalutamide?
MediHelp also lists interactions of Apalutamide with, for example, Cabotegravir, Cobicistat, Doravirine. The full list is on the Apalutamide page.
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