Drug interactions
Leuprolide + Toremifene
Severity: Major
Leuprolide 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 prolongs the QT interval in a dose-related way, and leuprolide may add to the effect. Using them together increases the risk of torsades de pointes.
What this interaction means in plain words
Leuprolide 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.
Leuprolide belongs to Endocrine; Toremifene belongs to Endocrine.
Why it happens
Additive QT prolongation from androgen deprivation (leuprolide) and toremifene blockade of cardiac potassium channels.
What to do
Avoid the combination where possible. If it is needed, monitor the ECG and electrolytes regularly and stop toremifene if the 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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Other interactions of Leuprolide
- Leuprolide + Pimozide Contraindicated
- Leuprolide + Thioridazine Contraindicated
- Amisulpride + Leuprolide Major
- Arsenic trioxide + Leuprolide Major
- Artemether / lumefantrine + Leuprolide Major
- Disopyramide + Leuprolide 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 Leuprolide with Toremifene?
MediHelp rates the interaction as major. Leuprolide 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 prolongs the QT interval in a dose-related way, and leuprolide may add to the effect. Using them together increases the risk of torsades de pointes.
How serious is the interaction between Leuprolide 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 where possible. If it is needed, monitor the ECG and electrolytes regularly and stop toremifene if the QTc becomes markedly prolonged.
What other medicines interact with Leuprolide?
MediHelp also lists interactions of Leuprolide with, for example, Pimozide, Thioridazine, Amisulpride. The full list is on the Leuprolide page.
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