Drug interactions
Guanfacine + Nicardipine
Severity: Moderate
Guanfacine and Nicardipine: 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 is cleared by CYP3A4, and inhibitors raise its levels. Nicardipine is a weak to moderate inhibitor and also lowers blood pressure, so combined hypotension, bradycardia and sedation are possible.
What this interaction means in plain words
Guanfacine and Nicardipine 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; Nicardipine belongs to Cardiovascular.
Why it happens
CYP3A4 inhibition by nicardipine reduces guanfacine clearance, plus additive hypotensive effects.
What to do
Monitor blood pressure, heart rate and sedation, and consider a lower guanfacine dose if adverse effects appear.
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 Nicardipine
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 Nicardipine?
MediHelp rates the interaction as moderate. Guanfacine and Nicardipine 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 is cleared by CYP3A4, and inhibitors raise its levels. Nicardipine is a weak to moderate inhibitor and also lowers blood pressure, so combined hypotension, bradycardia and sedation are possible.
How serious is the interaction between Guanfacine and Nicardipine?
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, and consider a lower guanfacine dose if adverse effects appear.
What other medicines interact with Nicardipine?
MediHelp also lists interactions of Nicardipine with, for example, Amifostine, Amlodipine-olmesartan-hydrochlorothiazide, Betrixaban. The full list is on the Nicardipine page.
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