Isosorbide dinitrate and hydralazine and Tadalafil interaction
Isosorbide dinitrate and hydralazine and Tadalafil: 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 Isosorbide dinitrate and hydralazine (Isosorbide dinitrate and hydralazine hydrochloride) label · effective 2025-06-03
Do not use isosorbide dinitrate and hydralazine hydrochloride tablets in patients who are taking PDE-5 inhibitors, such as avanafil, sildenafil, tadalafil, or vardenafil.
Use of phosphodiesterase type 5 (PDE5) inhibitors, such as avanafil, sildenafil, tadalafil, or vardenafil, or soluble guanylate cyclase (sGC) stimulator (riociguat).
Phosphodiesterase Inhibitors Isosorbide dinitrate and hydralazine hydrochloride tablets are contraindicated in patients who are using a selective inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5), PDE5 inhibitors such as avanafil, sildenafil, vardenafil, and tadalafil have been shown to potentiate the hypotensive effects…
From the Tadalafil (Cialis) label · effective 2026-06-03
Administration of CIALIS to patients using any form of organic nitrate is contraindicated.
CIALIS was shown to potentiate the hypotensive effect of nitrates ( 4.1 ).
Nitrates Administration of CIALIS to patients who are using any form of organic nitrate, either regularly and/or intermittently, is contraindicated.
In clinical pharmacology studies, CIALIS was shown to potentiate the hypotensive effect of nitrates [see Clinical Pharmacology ( 12.2 )] .
In such a patient, who has taken CIALIS, where nitrate administration is deemed medically necessary for a life-threatening situation, at least 48 hours should have elapsed after the last dose of CIALIS before nitrate administration is considered.
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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.