Do PDE5 inhibitors (Viagra, Cialis) affect cardiovascular health?

PDE5 inhibitors (sildenafil, tadalafil, vardenafil) are vasodilators that act by preventing the breakdown of cyclic GMP in vascular smooth muscle, and they are safe in men without cardiovascular disease and in men whose cardiovascular disease is hemodynamically stable, but they are absolutely contraindicated with nitrate medications (nitroglycerin, isosorbide) because the combination produces severe and potentially fatal hypotension (Kloner, Eur Heart J, 2006).

Beyond the nitrate contraindication, there is growing evidence that chronic PDE5 inhibitor use may have cardioprotective properties: tadalafil and sildenafil appear to reduce pulmonary arterial pressure, and retrospective data suggests men on chronic PDE5 inhibitors have lower rates of major adverse cardiovascular events than untreated hypogonadal or ED-affected men. These are observational findings, not RCT evidence for cardiac protection. The cardiologically relevant point is that if a man is using a nitrate for angina, his PDE5 inhibitor use must be managed carefully, this is a clinical conversation that many men are not having with their physicians.

Honesty Scale: Solid (1) for the nitrate-PDE5 inhibitor contraindication. Promising (2) for potential cardioprotective effects of chronic PDE5 inhibitor use.

What to do: If you take any nitrate medication (nitroglycerin pills for chest pain, isosorbide, or spray formulations) and are considering a PDE5 inhibitor, tell your prescribing physician. This is not a question to ask the pharmacist, it is a cardiovascular consultation.

For the full picture, read The Stamina Deep Dive