Drug interactions
Amiodarone + Promethazine
Severity: Major
Amiodarone and Promethazine: 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
Both drugs can prolong the QT interval, so combined use raises the risk of torsades de pointes. Amiodarone has a long half-life, so the risk persists after stopping it.
What this interaction means in plain words
Amiodarone and Promethazine 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.
Amiodarone belongs to Cardiovascular; Promethazine belongs to Respiratory.
Why it happens
Additive QT prolongation through cardiac potassium channel blockade.
What to do
Avoid if possible and use a non-QT-prolonging antiemetic or antihistamine; otherwise monitor ECG and keep potassium and magnesium normal.
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 Amiodarone and Promethazine, 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 14 days on the web. No card needed.
Other interactions of Promethazine
- Ibutilide + Promethazine Contraindicated
- Pimozide + Promethazine Contraindicated
- Promethazine + Thioridazine Contraindicated
- Alfentanil + Promethazine Major
- Amisulpride + Promethazine Major
- Belladonna and opium + Promethazine Major
Other interactions of Amiodarone
- Amiodarone + Amisulpride Contraindicated
- Amiodarone + Arsenic trioxide Contraindicated
- Amiodarone + Dofetilide Contraindicated
- Amiodarone + Dronedarone Contraindicated
- Amiodarone + Droperidol Contraindicated
- Amiodarone + Eliglustat Contraindicated
Frequently asked questions
Can I take Amiodarone with Promethazine?
MediHelp rates the interaction as major. Amiodarone and Promethazine 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. Both drugs can prolong the QT interval, so combined use raises the risk of torsades de pointes. Amiodarone has a long half-life, so the risk persists after stopping it.
How serious is the interaction between Amiodarone and Promethazine?
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 if possible and use a non-QT-prolonging antiemetic or antihistamine; otherwise monitor ECG and keep potassium and magnesium normal.
What other medicines interact with Promethazine?
MediHelp also lists interactions of Promethazine with, for example, Ibutilide, Pimozide, Thioridazine. The full list is on the Promethazine 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.
