Dutasteride and tamsulosin and Tamsulosin interaction
Dutasteride and tamsulosin and Tamsulosin: 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
Patients with previously demonstrated, clinically significant hypersensitivity (e.g., serious skin reactions, angioedema, urticaria, pruritus, respiratory symptoms) to dutasteride, other 5-alpha-reductase inhibitors, tamsulosin, or any other component of JALYN [see Adverse Reactions (6.2) ] .
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 Tamsulosin (Tamsulosin Hydrochloride) label · effective 2026-08-12
• Should not be used in combination with other alpha adrenergic blocking agents ( 5.2 , 7.2 , 12.3 )
…should be used with caution in combination with cimetidine, particularly at a dose higher than 0.4 mg (e.g., 0.8 mg) [see Drug Interactions ( 7.1 ) and Clinical Pharmacology ( 12.3 )] Tamsulosin hydrochloride capsules should not be used in combination with other alpha adrenergic blocking agents [see Drug Interactions ( 7.2 ) and Clinical Pharmacology ( 12.3 )] .
As with other alpha adrenergic blocking agents there is a potential risk of syncope [see Adverse Reactions ( 6.1 )] .
Other Alpha Adrenergic Blocking Agents The pharmacokinetic and pharmacodynamic interactions between tamsulosin hydrochloride capsules and other alpha adrenergic blocking agents have not been determined; however, interactions between tamsulosin hydrochloride capsules and other alpha adrenergic blocking agents may be expected [see Warnings and Precautions ( 5.2…
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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.