Drug interactions
Haloperidol + Venlafaxine
Severity: Major
Haloperidol and Venlafaxine: 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
Venlafaxine may modestly raise haloperidol exposure through weak CYP2D6 inhibition, and both drugs can prolong the QTc interval. Rare serotonin syndrome or neuroleptic malignant syndrome is also possible with combined serotonergic and dopamine-blocking activity.
What this interaction means in plain words
Haloperidol and Venlafaxine 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; Venlafaxine belongs to Central Nervous System.
Why it happens
Additive QT prolongation with weak CYP2D6 inhibition and additive serotonergic and dopaminergic effects.
What to do
Obtain a baseline ECG and monitor QTc, keeping potassium and magnesium normal. Use the lowest effective haloperidol dose and watch for extrapyramidal symptoms, serotonin toxicity and neuroleptic malignant syndrome.
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 Venlafaxine
- Isocarboxazid + Venlafaxine Contraindicated
- Methylene blue + Venlafaxine Contraindicated
- Phenelzine + Venlafaxine Contraindicated
- Procarbazine + Venlafaxine Contraindicated
- Rasagiline + Venlafaxine Contraindicated
- Safinamide + Venlafaxine 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 Venlafaxine?
MediHelp rates the interaction as major. Haloperidol and Venlafaxine 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. Venlafaxine may modestly raise haloperidol exposure through weak CYP2D6 inhibition, and both drugs can prolong the QTc interval. Rare serotonin syndrome or neuroleptic malignant syndrome is also possible with combined serotonergic and dopamine-blocking activity.
How serious is the interaction between Haloperidol and Venlafaxine?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Obtain a baseline ECG and monitor QTc, keeping potassium and magnesium normal. Use the lowest effective haloperidol dose and watch for extrapyramidal symptoms, serotonin toxicity and neuroleptic malignant syndrome.
What other medicines interact with Venlafaxine?
MediHelp also lists interactions of Venlafaxine with, for example, Isocarboxazid, Methylene blue, Phenelzine. The full list is on the Venlafaxine page.
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