Viagra is an effective treatment for men with erectile dysfunction.
Since its approval from the FDA in March 1998, more than 1 million prescriptions have been filed in the United States.

However, VIAGRA must not be used with nitroglycerin
or similar drugs used to treat the chest pains of heart disease.

The danger is that Viagra and nitroglycerin combined can make
your blood pressure plunge to a dangerously low level;
you could get dizzy, faint, or even have a heart attack or stroke.

Nitrates are found in many prescription medications that are
used to treat angina (chest pain due to heart disease) such as:

• Nitroglycerin (sprays, ointments, skin patches or pastes, and tablets that are swallowed or dissolved in the mouth)
• Isosorbide mononitrate and isosorbide dinitrate (tablets that are swallowed, chewed, or dissolved in the mouth)
• Nitrates are also found in recreational drugs such as amyl nitrate or nitrite ("poppers").

Viagra should not be taken if you have severe heart disease or are unable to tolerate normal sexual activity.

The amount of energy necessary to have normal sexual activity
is roughly equivalent to the ability of climbing one flight of stairs
without chest discomfort - if you are unsure, see a phyisician.

The following is a list of organic nitrates.
This list is illustrative only (i.e. is not all-inclusive).