Drug interactions
Haloperidol + Protriptyline
Severity: Major
Haloperidol and Protriptyline: 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 QT, and tricyclic antidepressants may also cause conduction delay. The combination increases arrhythmia risk, and protriptyline may raise haloperidol levels through CYP2D6 inhibition.
What this interaction means in plain words
Haloperidol and Protriptyline 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.
Why it happens
Additive QT prolongation, with possible CYP2D6 inhibition by protriptyline raising haloperidol levels.
What to do
Avoid combination if possible and consider a less QT-active antidepressant. If used, obtain a baseline ECG, monitor it and correct electrolytes.
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 Haloperidol and Protriptyline, 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 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 Protriptyline?
MediHelp rates the interaction as major. Haloperidol and Protriptyline 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 QT, and tricyclic antidepressants may also cause conduction delay. The combination increases arrhythmia risk, and protriptyline may raise haloperidol levels through CYP2D6 inhibition.
How serious is the interaction between Haloperidol and Protriptyline?
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 combination if possible and consider a less QT-active antidepressant. If used, obtain a baseline ECG, monitor it and correct electrolytes.
What other medicines interact with Haloperidol?
MediHelp also lists interactions of Haloperidol with, for example, Dofetilide, Dronedarone, Ibutilide. The full list is on the Haloperidol 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.
