Phentolamine and Silodosin interaction
Phentolamine 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) ].
As with other alpha-blockers, there is potential for syncope.
Pharmacodynamic Drug-Drug Interactions The pharmacodynamic interactions between silodosin and other alpha-blockers have not been determined.
From the Phentolamine (Oraverse) label · effective 2018-12-05
Tachycardia and cardiac arrhythmiasmay occur with the use of phentolamine or other alpha-adrenergic blocking agents.
Tachycardia and cardiac arrhythmias may occur with the use of phentolamine or other alpha-adrenergic blocking agents.
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.