Drug interactions
Penbutolol + Prazosin
Severity: Moderate
Penbutolol 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 agents reduce blood pressure, so the combination can produce greater hypotension than either alone, especially after the first prazosin dose. Beta blockade may blunt compensatory tachycardia, making dizziness and syncope more likely.
What this interaction means in plain words
Penbutolol 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.
Why it happens
Additive antihypertensive effect from alpha-1 blockade and nonselective beta blockade.
What to do
Begin prazosin at a low dose at bedtime and titrate gradually. Monitor standing blood pressure and warn the patient about orthostatic symptoms.
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 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 Penbutolol with Prazosin?
MediHelp rates the interaction as moderate. Penbutolol 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 agents reduce blood pressure, so the combination can produce greater hypotension than either alone, especially after the first prazosin dose. Beta blockade may blunt compensatory tachycardia, making dizziness and syncope more likely.
How serious is the interaction between Penbutolol 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: Begin prazosin at a low dose at bedtime and titrate gradually. Monitor standing blood pressure and warn the patient about orthostatic symptoms.
What other medicines interact with Prazosin?
MediHelp also lists interactions of Prazosin with, for example, Alfuzosin, Amifostine, Avanafil. The full list is on the Prazosin page.
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