Drug interactions
Gemfibrozil + Tucatinib
Severity: Major
Gemfibrozil 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 metabolized mainly by CYP2C8, and gemfibrozil is a strong CYP2C8 inhibitor. Tucatinib exposure rises substantially, increasing the risk of diarrhea and hepatotoxicity.
What this interaction means in plain words
Gemfibrozil 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.
Gemfibrozil belongs to Cardiovascular; Tucatinib belongs to Oncology.
Why it happens
Gemfibrozil and its glucuronide inhibit CYP2C8, reducing tucatinib clearance.
What to do
Avoid concurrent use and choose another lipid-lowering agent. If unavoidable, reduce the tucatinib dose per labeling and monitor liver tests and diarrhea.
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 Gemfibrozil
- Daprodustat + Gemfibrozil Contraindicated
- Elagolix + Gemfibrozil Contraindicated
- Gemfibrozil + Mavacamten Contraindicated
- Gemfibrozil + Metformin-repaglinide Contraindicated
- Gemfibrozil + Ombitasvir / paritaprevir / ritonavir and dasabuvir Contraindicated
- Gemfibrozil + Repaglinide 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 Gemfibrozil with Tucatinib?
MediHelp rates the interaction as major. Gemfibrozil 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 metabolized mainly by CYP2C8, and gemfibrozil is a strong CYP2C8 inhibitor. Tucatinib exposure rises substantially, increasing the risk of diarrhea and hepatotoxicity.
How serious is the interaction between Gemfibrozil 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 and choose another lipid-lowering agent. If unavoidable, reduce the tucatinib dose per labeling and monitor liver tests and diarrhea.
What other medicines interact with Gemfibrozil?
MediHelp also lists interactions of Gemfibrozil with, for example, Daprodustat, Elagolix, Mavacamten. The full list is on the Gemfibrozil page.
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