Drug interactions
Haloperidol + Mirtazapine
Severity: Moderate
Haloperidol and Mirtazapine: moderate 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 cause sedation and both can prolong the QT interval, with haloperidol having the greater proarrhythmic potential, especially at high doses or intravenously. Combined use increases drowsiness, psychomotor impairment and the risk of torsades de pointes.
What this interaction means in plain words
Haloperidol and Mirtazapine can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Haloperidol belongs to Central Nervous System; Mirtazapine belongs to Central Nervous System.
Why it happens
Additive CNS depression through histamine H1 blockade and additive QT prolongation.
What to do
Use the lowest effective haloperidol dose and obtain a baseline ECG, with repeat monitoring if doses rise or other QT-prolonging drugs are added. Correct electrolytes and advise patients about sedation and driving.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Haloperidol and Mirtazapine, 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 Mirtazapine
- Isocarboxazid + Mirtazapine Contraindicated
- Mirtazapine + Phenelzine Contraindicated
- Mirtazapine + Pimozide Contraindicated
- Mirtazapine + Procarbazine Contraindicated
- Mirtazapine + Rasagiline Contraindicated
- Mirtazapine + Selegiline 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 Mirtazapine?
MediHelp rates the interaction as moderate. Haloperidol and Mirtazapine can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Both drugs cause sedation and both can prolong the QT interval, with haloperidol having the greater proarrhythmic potential, especially at high doses or intravenously. Combined use increases drowsiness, psychomotor impairment and the risk of torsades de pointes.
How serious is the interaction between Haloperidol and Mirtazapine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Use the lowest effective haloperidol dose and obtain a baseline ECG, with repeat monitoring if doses rise or other QT-prolonging drugs are added. Correct electrolytes and advise patients about sedation and driving.
What other medicines interact with Mirtazapine?
MediHelp also lists interactions of Mirtazapine with, for example, Isocarboxazid, Phenelzine, Pimozide. The full list is on the Mirtazapine 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.
