Drug interactions
Azithromycin + Toremifene
Severity: Major
Azithromycin and Toremifene: major interaction.
Last updated Sources: UK SmPC
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 azithromycin adds to the effect. The combination may increase the risk of torsades de pointes.
What this interaction means in plain words
Azithromycin 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.
Azithromycin belongs to Anti Bacterial; Toremifene belongs to Endocrine.
Why it happens
Additive pharmacodynamic QT prolongation.
What to do
Avoid the combination and use a non-QT-prolonging antibiotic. If azithromycin is essential, consider interrupting toremifene, or otherwise 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?
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References
- Azithromycin 200mg/5ml Powder for Oral Suspension - SmPC sections 4.3/4.5 (class statement: medicinal products known to prolong the QT interval; "Azithromycin should be used with caution in patients receiving medicinal products known to prolong the QT interval") — electronic medicines compendium (UK SmPC)
Other interactions of Azithromycin
- Azithromycin + Cisapride Contraindicated
- Azithromycin + Domperidone Contraindicated
- Azithromycin + Dronedarone Contraindicated
- Azithromycin + Pimozide Contraindicated
- Azithromycin + Piperaquine Contraindicated
- Azithromycin + 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 Azithromycin with Toremifene?
MediHelp rates the interaction as major. Azithromycin 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 azithromycin adds to the effect. The combination may increase the risk of torsades de pointes.
How serious is the interaction between Azithromycin 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 and use a non-QT-prolonging antibiotic. If azithromycin is essential, consider interrupting toremifene, or otherwise monitor ECG and electrolytes closely.
What other medicines interact with Azithromycin?
MediHelp also lists interactions of Azithromycin with, for example, Cisapride, Domperidone, Dronedarone. The full list is on the Azithromycin page.
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