Drug interactions
Dofetilide + Risperidone
Severity: Major
Dofetilide and Risperidone: 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
Dofetilide strongly prolongs the QT interval and has a high torsades de pointes risk. Risperidone adds a smaller QT effect, making the combination hazardous.
What this interaction means in plain words
Dofetilide and Risperidone 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.
Dofetilide belongs to Cardiovascular; Risperidone belongs to Central Nervous System.
Why it happens
Additive prolongation of cardiac repolarization through potassium channel blockade.
What to do
Avoid the combination where possible and choose an antipsychotic with lower QT liability. If unavoidable, monitor the ECG and electrolytes closely, particularly during dofetilide initiation in hospital.
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
- Okedi 100mg powder and solvent for prolonged-release suspension for injection pre-filled syringes - SmPC sections 4.3/4.5 (class statement: antiarrhythmics; "Caution is advised when prescribing OKEDI with medicinal products known to prolong the QT interval, such as antiarrhythmics (e.g., quinidine,… — electronic medicines compendium (UK SmPC)
Other interactions of Risperidone
- Ibutilide + Risperidone Contraindicated
- Risperidone + Vandetanib Contraindicated
- Adagrasib + Risperidone Major
- Amiodarone + Risperidone Major
- Amisulpride + Risperidone Major
- Amoxapine + Risperidone Major
Other interactions of Dofetilide
- Amiodarone + Dofetilide Contraindicated
- Amisulpride + Dofetilide Contraindicated
- Amlodipine-hydrochlorothiazide-valsartan + Dofetilide Contraindicated
- Amlodipine-olmesartan-hydrochlorothiazide + Dofetilide Contraindicated
- Candesartan-hydrochlorothiazide + Dofetilide Contraindicated
- Captopril-hydrochlorothiazide + Dofetilide Contraindicated
Frequently asked questions
Can I take Dofetilide with Risperidone?
MediHelp rates the interaction as major. Dofetilide and Risperidone 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. Dofetilide strongly prolongs the QT interval and has a high torsades de pointes risk. Risperidone adds a smaller QT effect, making the combination hazardous.
How serious is the interaction between Dofetilide and Risperidone?
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 choose an antipsychotic with lower QT liability. If unavoidable, monitor the ECG and electrolytes closely, particularly during dofetilide initiation in hospital.
What other medicines interact with Risperidone?
MediHelp also lists interactions of Risperidone with, for example, Ibutilide, Vandetanib, Adagrasib. The full list is on the Risperidone page.
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