Why can't I take an ED drug if I have low blood pressure?

Drugs that treat erectile dysfunction can lower blood pressure temporarily, and that can cause medical problems if you already have uncontrolled low blood pressure. We all know that high blood pressure (anything over 120/80) is unhealthy. In general, lower blood pressure is healthy. But certain conditions, including certain kinds of heart disease, can cause blood pressure to be too low. Using an ED drug that further lowers your blood pressure is dangerous under these circumstances. Work with your doctor to maintain your health while treating your ED.

Viagra (sildenafil), Cialis (tadalafil), or Levitra (vardenafil) are not safe to take if you have low blood pressure. In addition, taking drugs for erectile dysfunction (ED) along with alpha blockers like doxazosin mesylate (Cardura), prazosin hydrochloride (Minipress), and terazosin (Hytrin) to lower high blood pressure -- or with nitroglycerin and other nitrate-based drugs (for example, Isordil, Monoket, and Nitrostat) -- can cause a sudden, unsafe decrease in blood pressure.

If you have low blood pressure, or are taking an alpha blocker or a nitrate-based drug, talk to your doctor about ED treatment that is right for you.