Drug interactions
Clonidine + Prazosin
Severity: Moderate
Clonidine and Prazosin: 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 lower blood pressure by different sympatholytic mechanisms, so combined use can cause additive hypotension, including first-dose orthostatic syncope. Clonidine may also cause bradycardia.
What this interaction means in plain words
Clonidine and Prazosin 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.
Clonidine belongs to Cardiovascular; Prazosin belongs to Genitourinary.
Why it happens
Additive hypotension from central alpha-2 agonism and peripheral alpha-1 blockade.
What to do
Start low and titrate, monitoring supine and standing blood pressure and heart rate. Counsel patients to rise slowly and adjust doses if dizziness occurs.
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 Clonidine
- Acebutolol + Clonidine Major
- Amifostine + Clonidine Major
- Amiodarone + Clonidine Major
- Amoxapine + Clonidine Major
- Atenolol-chlorthalidone + Clonidine Major
- Atenolol + Clonidine Major
Other interactions of Prazosin
- Alfuzosin + Prazosin Major
- Amifostine + Prazosin Major
- Avanafil + Prazosin Major
- Doxazosin + Prazosin Major
- Dutasteride-tamsulosin + Prazosin Major
- Phenoxybenzamine + Prazosin Major
Frequently asked questions
Can I take Clonidine with Prazosin?
MediHelp rates the interaction as moderate. Clonidine and Prazosin 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 lower blood pressure by different sympatholytic mechanisms, so combined use can cause additive hypotension, including first-dose orthostatic syncope. Clonidine may also cause bradycardia.
How serious is the interaction between Clonidine and Prazosin?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Start low and titrate, monitoring supine and standing blood pressure and heart rate. Counsel patients to rise slowly and adjust doses if dizziness occurs.
What other medicines interact with Clonidine?
MediHelp also lists interactions of Clonidine with, for example, Acebutolol, Amifostine, Amiodarone. The full list is on the Clonidine page.
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