Drug interactions
Doxepin + Pimozide
Severity: Major
Doxepin and Pimozide: major interaction.
Last updated Sources: US FDA label
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
Doxepin, a tricyclic antidepressant, can prolong the QT interval and is metabolized by CYP2D6 and CYP2C19. Combined with pimozide, there is an increased risk of arrhythmia.
What this interaction means in plain words
Doxepin and Pimozide 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.
Doxepin belongs to Dermatology; Pimozide belongs to Central Nervous System.
Why it happens
Additive QT prolongation and anticholinergic effects.
What to do
Avoid the combination where possible and choose an antidepressant with less QT liability. If used, obtain an ECG 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?
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References
Other interactions of Pimozide
- Adagrasib + Pimozide Contraindicated
- Amiodarone + Pimozide Contraindicated
- Amisulpride + Pimozide Contraindicated
- Amitriptyline + Pimozide Contraindicated
- Amoxapine + Pimozide Contraindicated
- Anagrelide + Pimozide Contraindicated
Other interactions of Doxepin
- Doxepin + Isocarboxazid Contraindicated
- Doxepin + Phenelzine Contraindicated
- Doxepin + Procarbazine Contraindicated
- Doxepin + Safinamide Contraindicated
- Doxepin + Selegiline Contraindicated
- Doxepin + Tranylcypromine Contraindicated
Frequently asked questions
Can I take Doxepin with Pimozide?
MediHelp rates the interaction as major. Doxepin and Pimozide 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. Doxepin, a tricyclic antidepressant, can prolong the QT interval and is metabolized by CYP2D6 and CYP2C19. Combined with pimozide, there is an increased risk of arrhythmia.
How serious is the interaction between Doxepin and Pimozide?
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 the combination where possible and choose an antidepressant with less QT liability. If used, obtain an ECG and correct electrolytes.
What other medicines interact with Pimozide?
MediHelp also lists interactions of Pimozide with, for example, Adagrasib, Amiodarone, Amisulpride. The full list is on the Pimozide page.
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