Drug interactions
Doxazosin + Tizanidine
Severity: Moderate
Doxazosin 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
Tizanidine lowers blood pressure and can cause hypotension, dizziness and sedation. Combined with doxazosin the risk of symptomatic hypotension and syncope is increased.
What this interaction means in plain words
Doxazosin 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.
Doxazosin belongs to Genitourinary; Tizanidine belongs to Musculoskeletal.
Why it happens
Additive hypotension from central alpha-2 agonism by tizanidine and peripheral alpha-1 blockade by doxazosin.
What to do
Monitor blood pressure and start tizanidine at a low dose. Reduce the dose of one agent if orthostatic symptoms develop.
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 Doxazosin
- Alfuzosin + Doxazosin Major
- Amifostine + Doxazosin Major
- Avanafil + Doxazosin Major
- Doxazosin + Dutasteride-tamsulosin Major
- Doxazosin + Phentolamine Major
- Doxazosin + Prazosin Major
Other interactions of Tizanidine
- Ciprofloxacin + Tizanidine Contraindicated
- Fluvoxamine + Tizanidine Contraindicated
- Pefloxacin + Tizanidine Contraindicated
- Pipemidic acid + Tizanidine Contraindicated
- Benzhydrocodone / acetaminophen + Tizanidine Major
- Brexanolone + Tizanidine Major
Frequently asked questions
Can I take Doxazosin with Tizanidine?
MediHelp rates the interaction as moderate. Doxazosin 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. Tizanidine lowers blood pressure and can cause hypotension, dizziness and sedation. Combined with doxazosin the risk of symptomatic hypotension and syncope is increased.
How serious is the interaction between Doxazosin 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 and start tizanidine at a low dose. Reduce the dose of one agent if orthostatic symptoms develop.
What other medicines interact with Doxazosin?
MediHelp also lists interactions of Doxazosin with, for example, Alfuzosin, Amifostine, Avanafil. The full list is on the Doxazosin page.
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