Drug interactions
Imatinib + Toremifene
Severity: Major
Imatinib and Toremifene: 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
Toremifene is metabolized by CYP3A4 and imatinib inhibits this enzyme, which may raise toremifene levels. Toremifene prolongs the QT interval in a dose-related way, so higher exposure raises arrhythmia risk. Imatinib has also been linked to QT effects in rare cases.
What this interaction means in plain words
Imatinib and Toremifene 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.
Imatinib belongs to Oncology; Toremifene belongs to Endocrine.
Why it happens
Imatinib inhibits CYP3A4-mediated metabolism of toremifene, adding to its QT-prolonging effects.
What to do
Obtain a baseline ECG, correct potassium and magnesium, and monitor the QTc during therapy. Avoid the combination in patients with QT risk factors.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Imatinib and Toremifene, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 14 days on the web. No card needed.
Other interactions of Imatinib
- Imatinib + Lomitapide Contraindicated
- Imatinib + Lonafarnib Contraindicated
- Amobarbital + Imatinib Major
- Apalutamide + Imatinib Major
- Avapritinib + Imatinib Major
- Benzhydrocodone / acetaminophen + Imatinib Major
Other interactions of Toremifene
- Amiodarone + Toremifene Contraindicated
- Dronedarone + Toremifene Contraindicated
- Nilotinib + Toremifene Contraindicated
- Pimozide + Toremifene Contraindicated
- Quinidine + Toremifene Contraindicated
- Ribociclib + Toremifene Contraindicated
Frequently asked questions
Can I take Imatinib with Toremifene?
MediHelp rates the interaction as major. Imatinib and Toremifene 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. Toremifene is metabolized by CYP3A4 and imatinib inhibits this enzyme, which may raise toremifene levels. Toremifene prolongs the QT interval in a dose-related way, so higher exposure raises arrhythmia risk. Imatinib has also been linked to QT effects in rare cases.
How serious is the interaction between Imatinib and Toremifene?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Obtain a baseline ECG, correct potassium and magnesium, and monitor the QTc during therapy. Avoid the combination in patients with QT risk factors.
What other medicines interact with Imatinib?
MediHelp also lists interactions of Imatinib with, for example, Lomitapide, Lonafarnib, Amobarbital. The full list is on the Imatinib page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
