Doxazosin and Propranolol: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Doxazosin
Propranolol
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
An exaggerated hypotensive response to the first dose of the alpha blocker
Interaction Deep Dive
In patients currently on beta blockers, the first dose response (marked initial drop in blood pressure, particularly on standing) to an alpha-1 adrenergic blocking drug may be exaggerated12. These effects may be less marked with alpha blockers other than prazosin 34, but caution should still be exercised with all alpha blockers. The lowest possible initial dose should be used and the first dose should preferably be given at bedtime. The addition of beta blocking drugs to ongoing alpha blocker therapy is much less likely to lead to a significant fall in blood pressure 2.
Why it happens (mechanism)
Suppression of beta-mediated compensatory increases in heart rate
Literature reports
1 report — tap to read
a) Administration of a single dose of atenolol 100 mg with a single dose of immediate-release alfuzosin 2.5 mg in 8 healthy young male subjects increased alfuzosin Cmax and AUC values by 28% and 21%, respectively. Alfuzosin increased atenolol Cmax and AUC values by 26% and 14%, respectively. The combination of alfuzosin with atenolol caused significant reductions in mean blood pressure and in mean heart rate in this study 5.
Common questions
Can I take Doxazosin and Propranolol together?
An exaggerated hypotensive response to the first dose of the alpha blocker Always confirm with your pharmacist or prescriber before making any change.
How serious is the Doxazosin and Propranolol interaction?
It is rated moderate. Can be significant — usually manageable with monitoring.
How quickly could this interaction happen?
The documented onset is "rapid". Effects can appear quickly, often within about 24 hours of combining the drugs.
How strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Doxazosin or Propranolol need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there anything you'd monitor while I'm on both?
References (5)
- Elliott HL, McLean K, Sumner DJ, et al: Immediate cardiovascular responses to oral prazosin: effects of concurrent beta-blockers. Clin Pharmacol Ther 1981; 29:303-309.
- Seideman P, Grahnen A, Haglund K, et al: Prazosin first dose phenomenon during combined treatment with a beta-adrenoceptor blocker in hypertensive patients. Br J Clin Pharmacol 1982; 13:865-870. PubMed
- Wilde M, Fitton A, & McTavish D: Alfuzosin: a review of its pharmacodynamic and pharmacokinetic properties, and therapeutic potential in benign prostatic hyperplasia. Drugs 1993; 45:410-429.
- Miller K: Pharmacological management of hypertension in paediatric patients. A comprehensive review of the efficacy, safety and dosage guidelines of the available agents. Drugs 1994; 48:868-887. PubMed
- Product Information: UROXATRAL(R) oral extended-release tablets, alfuzosin HCl oral extended-release tablets. Sanofi-Aventis US LLC, Bridgewater, NJ, 2008. DailyMed
Keep reading about Doxazosin
Keep reading about Propranolol
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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