Riociguat and Sildenafil interaction
Riociguat and Sildenafil: 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 Riociguat (Adempas) label · effective 2026-08-13
Do not administer within 24 hours of sildenafil.
Phosphodiesterase Inhibitors Concomitant administration of Adempas with specific PDE-5 inhibitors (such as sildenafil, tadalafil, or vardenafil) or nonspecific PDE-5 inhibitors (such as dipyridamole or theophylline) is contraindicated [see Dosage and Administration (2.6), Drug Interactions ( 7.1 ) and Clinical Pharmacology ( 12.2 )].
PDE Inhibitors: Co-administration of Adempas with specific PDE-5 inhibitors (such as sildenafil, tadalafil, or vardenafil) and nonspecific PDE inhibitors (such as dipyridamole or theophylline), is contraindicated because of hypotension.
Clinical experience with co-administration of Adempas and other phosphodiesterase inhibitors (for example, milrinone, cilostazole, roflumilast) is limited.
From the Sildenafil label · effective 2026-07-17
Administration with guanylate cyclase (GC) stimulators, such as riociguat.
Concomitant Guanylate Cyclase (GC) Stimulators Do not use SILDENAFIL ORAL FILM in patients who are using a GC stimulator, such as riociguat.
Blood Pressure Decreases Patients with left ventricular outflow obstruction (e.g., aortic stenosis, idiopathic hypertrophic subaortic stenosis) and those with severely impaired autonomic control of blood pressure can be sensitive to the actions of vasodilators, including SILDENAFIL ORAL FILM.
When vasodilators are used in combination, an additive effect on blood pressure may occur.
PDE5 inhibitors, including sildenafil, and alpha-adrenergic blocking agents are both vasodilators with blood pressure lowering effects.
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.