Alfuzosin and Doxazosin interaction

Alfuzosin and Doxazosin: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.

Major

Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.

What the FDA labels say

From the Alfuzosin (Uroxatral) label · effective 2024-12-05

Major

Should not be used in combination with other alpha adrenergic antagonists ( 5.4 , 7.2 )

Warnings and precautionsby drug classView label on DailyMed
Major

Other alpha adrenergic antagonists: UROXATRAL is an alpha adrenergic antagonist and should not be used in combination with other alpha adrenergic antagonist [see Drug Interactions (7.2) ].

Warnings and precautionsby drug classView label on DailyMed
Major

However, interactions may be expected, and UROXATRAL should not be used in combination with other alpha adrenergic antagonists [see Warnings and Precautions (5.4) ].

Drug interactionsby drug classView label on DailyMed
Moderate

Postural hypotension/syncope: Care should be taken in patients with symptomatic hypotension or who have had a hypotensive response to other medications or are concomitantly treated with antihypertensive medication or nitrates ( 5.1 )

Warnings and precautionsby drug classView label on DailyMed
Moderate

Antihypertensive Medication and Nitrates There may be an increased risk of hypotension/postural hypotension and syncope when taking UROXATRAL concomitantly with anti-hypertensive medication and nitrates [see Warnings and Precautions (5.1) ] .

Drug interactionsby drug classView label on DailyMed

From the Doxazosin (Doxazosin mesylate) label · effective 2025-11-24

Moderate

As with other alpha-blockers, there is a potential for syncope, especially after the initial dose or after an increase in dosage strength.

Warnings and precautionsby drug classView label on DailyMed

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Not medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.