Drug interactions
Granisetron + Toremifene
Severity: Major
Granisetron 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
Toremifene carries a boxed warning for dose-related QT prolongation, and its labeling advises against combining it with other QT-prolonging drugs. Granisetron adds to the risk of torsades de pointes.
What this interaction means in plain words
Granisetron 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.
Granisetron belongs to Gastrointestinal Tract; Toremifene belongs to Endocrine.
Why it happens
Additive prolongation of the QT interval.
What to do
Avoid the combination where possible and use an antiemetic with minimal QT effect. If used, monitor ECG and electrolytes closely.
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 Granisetron 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 7 days on the web. No card needed.
References
Other interactions of Granisetron
- Apomorphine + Granisetron Contraindicated
- Amiodarone + Granisetron Major
- Amisulpride + Granisetron Major
- Arsenic trioxide + Granisetron Major
- Artemether / lumefantrine + Granisetron Major
- Artemether + Granisetron 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 Granisetron with Toremifene?
MediHelp rates the interaction as major. Granisetron 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 carries a boxed warning for dose-related QT prolongation, and its labeling advises against combining it with other QT-prolonging drugs. Granisetron adds to the risk of torsades de pointes.
How serious is the interaction between Granisetron 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 and use an antiemetic with minimal QT effect. If used, monitor ECG and electrolytes closely.
What other medicines interact with Granisetron?
MediHelp also lists interactions of Granisetron with, for example, Apomorphine, Amiodarone, Amisulpride. The full list is on the Granisetron 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.
