Drug interactions
Guanfacine + Pimozide
Severity: Moderate
Guanfacine and Pimozide: 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
Guanfacine lowers blood pressure and heart rate and causes sedation, while pimozide can cause orthostatic hypotension and sedation. Combined use may produce additive hypotension, dizziness and drowsiness, and bradycardia may add to QT-related arrhythmia risk.
What this interaction means in plain words
Guanfacine and Pimozide 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.
Guanfacine belongs to Cardiovascular; Pimozide belongs to Central Nervous System.
Why it happens
Additive hypotensive and sedative effects from central alpha-2 agonism and alpha-adrenergic/dopamine blockade.
What to do
Monitor blood pressure, heart rate and sedation when starting or changing doses. Consider ECG monitoring because of pimozide's QT effects.
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?
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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 Guanfacine
- Clonidine + Guanfacine Major
- Guanfacine + Lofexidine Major
- Aldesleukin + Guanfacine Moderate
- Amiodarone + Guanfacine Moderate
- Amisulpride + Guanfacine Moderate
- Amitriptyline + Guanfacine Moderate
Frequently asked questions
Can I take Guanfacine with Pimozide?
MediHelp rates the interaction as moderate. Guanfacine and Pimozide 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. Guanfacine lowers blood pressure and heart rate and causes sedation, while pimozide can cause orthostatic hypotension and sedation. Combined use may produce additive hypotension, dizziness and drowsiness, and bradycardia may add to QT-related arrhythmia risk.
How serious is the interaction between Guanfacine and Pimozide?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor blood pressure, heart rate and sedation when starting or changing doses. Consider ECG monitoring because of pimozide's QT effects.
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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