Drug interactions
Haloperidol + Trazodone
Severity: Major
Haloperidol and Trazodone: 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 QTc, and haloperidol is well known to be associated with torsades de pointes, particularly at high or intravenous doses. The combination meaningfully increases arrhythmia risk.
What this interaction means in plain words
Haloperidol and Trazodone 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.
Haloperidol belongs to Central Nervous System; Trazodone belongs to Central Nervous System.
Why it happens
Additive blockade of cardiac potassium channels leading to QT prolongation.
What to do
Avoid if possible, or use the lowest effective doses with baseline and follow-up ECG and correction of potassium and magnesium.
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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Other interactions of Trazodone
- Arsenic trioxide + Trazodone Contraindicated
- Ibutilide + Trazodone Contraindicated
- Isocarboxazid + Trazodone Contraindicated
- Levoketoconazole + Trazodone Contraindicated
- Methylene blue + Trazodone Contraindicated
- Phenelzine + Trazodone Contraindicated
Other interactions of Haloperidol
- Dofetilide + Haloperidol Contraindicated
- Dronedarone + Haloperidol Contraindicated
- Haloperidol + Ibutilide Contraindicated
- Haloperidol + Levoketoconazole Contraindicated
- Haloperidol + Panobinostat Contraindicated
- Haloperidol + Pimozide Contraindicated
Frequently asked questions
Can I take Haloperidol with Trazodone?
MediHelp rates the interaction as major. Haloperidol and Trazodone 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 QTc, and haloperidol is well known to be associated with torsades de pointes, particularly at high or intravenous doses. The combination meaningfully increases arrhythmia risk.
How serious is the interaction between Haloperidol and Trazodone?
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, or use the lowest effective doses with baseline and follow-up ECG and correction of potassium and magnesium.
What other medicines interact with Trazodone?
MediHelp also lists interactions of Trazodone with, for example, Arsenic trioxide, Ibutilide, Isocarboxazid. The full list is on the Trazodone page.
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