Nitrates — nitroglycerin in any form, isosorbide products, and recreational 'poppers' containing amyl or butyl nitrite — increase nitric oxide signaling. PDE5 inhibitors amplify the downstream effect of that same signal. Combined, the blood-pressure drop can be severe and can cause fainting, injury or worse.
This is not a caution to weigh against convenience. It is an absolute contraindication in the labeling of these medications, and it applies to as-needed nitroglycerin you carry but rarely use.
Tell any clinician treating you for chest pain that you take a PDE5 inhibitor, and tell the prescriber of your erectile medication about every nitrate, including recreational ones. If you develop chest pain after taking a PDE5 inhibitor, seek emergency care and say what you have taken.
Risks and limitations
- The interaction can cause profound hypotension, fainting and serious injury.
- It applies to prescription nitrates and to recreational nitrite 'poppers'.
- Timing windows differ between medications and should never be self-managed.
- Certain alpha-blockers and other blood-pressure medicines also require caution.