Doxazosin and Silodosin interaction
Doxazosin and Silodosin: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Silodosin label · effective 2026-03-16
Silodosin capsules should not be used in combination with other alpha-blockers.
However, interactions may be expected, and silodosin capsules should not be used in combination with other alpha-blockers [see DRUG INTERACTIONS (7.3) ].
However, patients in the Phase 3 clinical studies taking concomitant antihypertensive medications with silodosin capsules did not experience a significant increase in the incidence of syncope, dizziness, or orthostasis.
Nevertheless, exercise caution during concomitant use with antihypertensives and monitor patients for possible adverse events [see ADVERSE REACTIONS (6.1)
Exercise caution during concomitant use with antihypertensives and monitor patients for possible adverse events [see WARNINGS AND PRECAUTIONS (5.5) ].
From the Doxazosin (Doxazosin mesylate) label · effective 2025-11-24
As with other alpha-blockers, there is a potential for syncope, especially after the initial dose or after an increase in dosage strength.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot 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.