Drug interactions
Crizotinib + Toremifene
Severity: Major
Crizotinib and Toremifene: major interaction.
Last updated Sources: US FDA label
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
Both agents prolong the QT interval, so concurrent use increases the risk of torsades de pointes. Toremifene labeling lists QT prolongation as a boxed warning.
What this interaction means in plain words
Crizotinib 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.
Crizotinib belongs to Oncology; Toremifene belongs to Endocrine.
Why it happens
Additive prolongation of cardiac repolarization (QTc).
What to do
Avoid the combination if possible; otherwise monitor ECG and electrolytes regularly and stop therapy if QTc becomes markedly prolonged.
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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References
Other interactions of Crizotinib
- Crizotinib + Flibanserin Contraindicated
- Crizotinib + Lomitapide Contraindicated
- Crizotinib + Lonafarnib Contraindicated
- Crizotinib + Pimozide Contraindicated
- Crizotinib + Saquinavir Contraindicated
- Crizotinib + Thioridazine Contraindicated
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 Crizotinib with Toremifene?
MediHelp rates the interaction as major. Crizotinib 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. Both agents prolong the QT interval, so concurrent use increases the risk of torsades de pointes. Toremifene labeling lists QT prolongation as a boxed warning.
How serious is the interaction between Crizotinib 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: Avoid the combination if possible; otherwise monitor ECG and electrolytes regularly and stop therapy if QTc becomes markedly prolonged.
What other medicines interact with Crizotinib?
MediHelp also lists interactions of Crizotinib with, for example, Flibanserin, Lomitapide, Lonafarnib. The full list is on the Crizotinib page.
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