Drug interactions
Doxazosin + Prazosin
Severity: Major
Doxazosin and Prazosin: major 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
Doxazosin and prazosin are both alpha-1 blockers, so combining them duplicates therapy and increases the risk of excessive hypotension, dizziness and syncope.
What this interaction means in plain words
Doxazosin and Prazosin can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Doxazosin belongs to Genitourinary; Prazosin belongs to Genitourinary.
Why it happens
Duplicate alpha-1 adrenergic receptor blockade with additive vasodilation.
What to do
Avoid using two alpha-1 blockers together and choose one agent. If transitioning, stop one drug before starting the other and monitor orthostatic blood pressure.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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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 + Sildenafil Major
Other interactions of Prazosin
- Alfuzosin + Prazosin Major
- Amifostine + Prazosin Major
- Avanafil + Prazosin Major
- Dutasteride-tamsulosin + Prazosin Major
- Phenoxybenzamine + Prazosin Major
- Prazosin + Sildenafil Major
Frequently asked questions
Can I take Doxazosin with Prazosin?
MediHelp rates the interaction as major. Doxazosin and Prazosin can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Doxazosin and prazosin are both alpha-1 blockers, so combining them duplicates therapy and increases the risk of excessive hypotension, dizziness and syncope.
How serious is the interaction between Doxazosin and Prazosin?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid using two alpha-1 blockers together and choose one agent. If transitioning, stop one drug before starting the other and monitor orthostatic blood pressure.
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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