Drug interactions
Guanfacine + Tizanidine
Severity: Moderate
Guanfacine and Tizanidine: 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 are central alpha-2 adrenergic agonists, so combined use can produce additive hypotension, bradycardia and sedation. The effects may be pronounced at initiation or dose increases.
What this interaction means in plain words
Guanfacine and Tizanidine 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; Tizanidine belongs to Musculoskeletal.
Why it happens
Duplicate central alpha-2 adrenergic agonism producing additive sympatholytic and sedative effects.
What to do
Monitor blood pressure, heart rate and sedation, and titrate doses slowly. Avoid abrupt discontinuation of guanfacine and reduce either dose if symptomatic.
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 Tizanidine
- Ciprofloxacin + Tizanidine Contraindicated
- Fluvoxamine + Tizanidine Contraindicated
- Pefloxacin + Tizanidine Contraindicated
- Pipemidic acid + Tizanidine Contraindicated
- Benzhydrocodone / acetaminophen + Tizanidine Major
- Brexanolone + Tizanidine 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 Guanfacine with Tizanidine?
MediHelp rates the interaction as moderate. Guanfacine and Tizanidine 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 are central alpha-2 adrenergic agonists, so combined use can produce additive hypotension, bradycardia and sedation. The effects may be pronounced at initiation or dose increases.
How serious is the interaction between Guanfacine and Tizanidine?
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 titrate doses slowly. Avoid abrupt discontinuation of guanfacine and reduce either dose if symptomatic.
What other medicines interact with Tizanidine?
MediHelp also lists interactions of Tizanidine with, for example, Ciprofloxacin, Fluvoxamine, Pefloxacin. The full list is on the Tizanidine page.
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