Dutasteride and tamsulosin and Phentolamine interaction
Dutasteride and tamsulosin and Phentolamine: 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 Dutasteride and tamsulosin (Jalyn) label · effective 2026-03-09
Do not use JALYN with other alpha-adrenergic antagonists, as this may increase the risk of hypotension.
Other Alpha-adrenergic Antagonists Tamsulosin-containing products, including JALYN, should not be coadministered with other alpha-adrenergic antagonists because of the increased risk of symptomatic hypotension.
Orthostatic Hypotension As with other alpha-adrenergic antagonists, orthostatic hypotension (postural hypotension, dizziness, and vertigo) may occur in patients treated with tamsulosin-containing products, including JALYN, and can result in syncope.
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.