Drug interactions
Simvastatin + Tucatinib
Severity: Major
Simvastatin 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
Tucatinib is a moderate CYP3A inhibitor and can increase simvastatin exposure. This raises the risk of dose-related myopathy and rhabdomyolysis.
What this interaction means in plain words
Simvastatin 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.
Simvastatin belongs to Cardiovascular; Tucatinib belongs to Oncology.
Why it happens
Inhibition of CYP3A4 by tucatinib decreases simvastatin first-pass and systemic metabolism.
What to do
Avoid the combination if possible, or limit simvastatin to a reduced dose and switch to a non-CYP3A4 statin if needed. Counsel patients to report muscle pain and check CK if symptoms occur.
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 Simvastatin
- Atazanavir + Simvastatin Contraindicated
- Clarithromycin + Simvastatin Contraindicated
- Cobicistat + Simvastatin Contraindicated
- Cyclosporine + Simvastatin Contraindicated
- Cyclosporin + Simvastatin Contraindicated
- Danazol + Simvastatin 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 Simvastatin with Tucatinib?
MediHelp rates the interaction as major. Simvastatin 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. Tucatinib is a moderate CYP3A inhibitor and can increase simvastatin exposure. This raises the risk of dose-related myopathy and rhabdomyolysis.
How serious is the interaction between Simvastatin 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 the combination if possible, or limit simvastatin to a reduced dose and switch to a non-CYP3A4 statin if needed. Counsel patients to report muscle pain and check CK if symptoms occur.
What other medicines interact with Simvastatin?
MediHelp also lists interactions of Simvastatin with, for example, Atazanavir, Clarithromycin, Cobicistat. The full list is on the Simvastatin page.
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