Drug interactions
Moxifloxacin + Ribociclib
Severity: Major
Moxifloxacin and Ribociclib: 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
Ribociclib causes dose-dependent QT prolongation, and its labeling advises against combining it with other QT-prolonging drugs such as moxifloxacin. The combination substantially raises the risk of torsades de pointes.
What this interaction means in plain words
Moxifloxacin and Ribociclib 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.
Moxifloxacin belongs to Anti Bacterial; Ribociclib belongs to Oncology.
Why it happens
Additive delay of ventricular repolarization through potassium channel effects.
What to do
Avoid the combination and use a different antibiotic. If unavoidable, monitor ECG and electrolytes closely and consider ribociclib dose interruption or reduction if QTc rises.
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
- Avelox 400 mg film-coated tablets - SmPC sections 4.3/4.5 (class statement: other medicinal products that may prolong the QTc interval; "An additive effect on QT interval prolongation of moxifloxacin and other medicinal products that may prolong the QTc interval cannot be excluded.") — electronic medicines compendium (UK SmPC)
Other interactions of Moxifloxacin
- Amiodarone + Moxifloxacin Contraindicated
- Arsenic trioxide + Moxifloxacin Contraindicated
- Disopyramide + Moxifloxacin Contraindicated
- Dofetilide + Moxifloxacin Contraindicated
- Dronedarone + Moxifloxacin Contraindicated
- Droperidol + Moxifloxacin Contraindicated
Other interactions of Ribociclib
- Amiodarone + Ribociclib Contraindicated
- Cisapride + Ribociclib Contraindicated
- Dofetilide + Ribociclib Contraindicated
- Dronedarone + Ribociclib Contraindicated
- Flibanserin + Ribociclib Contraindicated
- Ibutilide + Ribociclib Contraindicated
Frequently asked questions
Can I take Moxifloxacin with Ribociclib?
MediHelp rates the interaction as major. Moxifloxacin and Ribociclib 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. Ribociclib causes dose-dependent QT prolongation, and its labeling advises against combining it with other QT-prolonging drugs such as moxifloxacin. The combination substantially raises the risk of torsades de pointes.
How serious is the interaction between Moxifloxacin and Ribociclib?
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 different antibiotic. If unavoidable, monitor ECG and electrolytes closely and consider ribociclib dose interruption or reduction if QTc rises.
What other medicines interact with Moxifloxacin?
MediHelp also lists interactions of Moxifloxacin with, for example, Amiodarone, Arsenic trioxide, Disopyramide. The full list is on the Moxifloxacin page.
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