Drug interactions
Bretylium + Prazosin
Severity: Moderate
Bretylium 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
Bretylium blocks release of norepinephrine from sympathetic nerve terminals and itself commonly causes hypotension. Adding an alpha-1 blocker such as prazosin can increase the risk of marked or orthostatic hypotension.
What this interaction means in plain words
Bretylium 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 hypotension from presynaptic sympathetic neuron blockade plus postsynaptic alpha-1 receptor blockade.
What to do
Monitor blood pressure continuously when bretylium is given to a patient taking prazosin. Consider holding or lowering the prazosin dose and have fluids ready for hypotension.
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 Bretylium with Prazosin?
MediHelp rates the interaction as moderate. Bretylium 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. Bretylium blocks release of norepinephrine from sympathetic nerve terminals and itself commonly causes hypotension. Adding an alpha-1 blocker such as prazosin can increase the risk of marked or orthostatic hypotension.
How serious is the interaction between Bretylium 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: Monitor blood pressure continuously when bretylium is given to a patient taking prazosin. Consider holding or lowering the prazosin dose and have fluids ready for hypotension.
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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