Drug interactions
Guanfacine + Voriconazole
Severity: Moderate
Guanfacine and Voriconazole: 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
Voriconazole raises guanfacine concentrations, which can cause hypotension, bradycardia and sedation.
What this interaction means in plain words
Guanfacine and Voriconazole 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; Voriconazole belongs to Anti Fungals.
Why it happens
Voriconazole inhibits CYP3A4, the main route of guanfacine metabolism.
What to do
Halve the extended-release guanfacine dose during voriconazole therapy and monitor blood pressure and heart rate. Readjust the dose when voriconazole is discontinued.
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 Voriconazole
- Avanafil + Voriconazole Contraindicated
- Butabarbital + Voriconazole Contraindicated
- Carbamazepine + Voriconazole Contraindicated
- Conivaptan + Voriconazole Contraindicated
- Dihydroergotamine intranasal + Voriconazole Contraindicated
- Dihydroergotamine + Voriconazole 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 Voriconazole?
MediHelp rates the interaction as moderate. Guanfacine and Voriconazole 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. Voriconazole raises guanfacine concentrations, which can cause hypotension, bradycardia and sedation.
How serious is the interaction between Guanfacine and Voriconazole?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Halve the extended-release guanfacine dose during voriconazole therapy and monitor blood pressure and heart rate. Readjust the dose when voriconazole is discontinued.
What other medicines interact with Voriconazole?
MediHelp also lists interactions of Voriconazole with, for example, Avanafil, Butabarbital, Carbamazepine. The full list is on the Voriconazole page.
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