Drug interactions
Fluphenazine + Guanfacine
Severity: Moderate
Fluphenazine and Guanfacine: 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
Both drugs lower blood pressure and cause sedation, so combined use can lead to hypotension, dizziness, syncope and drowsiness. Older patients are most at risk of falls.
What this interaction means in plain words
Fluphenazine and Guanfacine 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.
Fluphenazine belongs to Central Nervous System; Guanfacine belongs to Cardiovascular.
Why it happens
Additive hypotensive and sedative effects from central alpha-2 agonism and phenothiazine alpha-1 blockade.
What to do
Monitor blood pressure, pulse and sedation, and titrate doses slowly. Advise patients to rise slowly and avoid abrupt guanfacine discontinuation.
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 Fluphenazine
- Arsenic trioxide + Fluphenazine Contraindicated
- Dofetilide + Fluphenazine Contraindicated
- Fluphenazine + Ibutilide Contraindicated
- Fluphenazine + Pimozide Contraindicated
- Adagrasib + Fluphenazine Major
- Alfentanil + Fluphenazine Major
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 Fluphenazine with Guanfacine?
MediHelp rates the interaction as moderate. Fluphenazine and Guanfacine 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. Both drugs lower blood pressure and cause sedation, so combined use can lead to hypotension, dizziness, syncope and drowsiness. Older patients are most at risk of falls.
How serious is the interaction between Fluphenazine and Guanfacine?
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, pulse and sedation, and titrate doses slowly. Advise patients to rise slowly and avoid abrupt guanfacine discontinuation.
What other medicines interact with Fluphenazine?
MediHelp also lists interactions of Fluphenazine with, for example, Arsenic trioxide, Dofetilide, Ibutilide. The full list is on the Fluphenazine page.
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