Who should avoid sildenafil or tadalafil for erectile dysfunction (ED)?

Sildenafil and tadalafil must not be combined with nitrate medicines, such as nitroglycerin or isosorbide, or recreational nitrites called “poppers.” They also must not be taken with riociguat. These combinations can lower blood pressure to a dangerous level. Tell your physician about medicines you use only occasionally, not just daily drugs.

Other medicines also need review. These include alpha blockers, blood pressure medicines, other ED treatments, and certain drugs used for infections. Kidney or liver disease can affect how your body handles ED medicine. A history of serious vision problems or prolonged erections also matters.

Tell your physician if you have chest pain, severe heart disease, very low blood pressure, or a recent heart attack or stroke. Sexual activity itself may not be safe for some people until they have been evaluated. If chest pain develops after taking ED medicine, stop sexual activity and seek emergency help. Do not take nitrates. Tell emergency staff exactly what ED medicine you took and when.