Viagra and nitrates both cause the muscles that control the size of blood vessels to relax. When these muscles relax, the vessels enlarge in diameter and, as a result, blood pressure drops. When Viagra and nitrates are taken together, the effects are greater than when either one is used alone. There may be a marked relaxation of the muscles that control the vessels with a great drop in blood pressure.

A drastic drop in blood pressure is detrimental to patients who have angina pectoris (heart pain), a condition in which a higher blood pressure is necessary to supply the heart with blood. Lowering the blood pressure decreases the flow of blood to the heart and can precipitate a heart attack.

Persons who are using medications containing nitrates should therefore NOT take Viagra. As of November 1998, 130 deaths had been associated with the use of Viagra in the U.S. Sixteen of the men who died had also taken a nitrate.

Since sexual activity or exercise can precipitate a heart attack in patients with angina pectoris, it may not have been the use of Viagra+ nitrates that was responsible for all of the deaths. However, it would seem better to be safe than sorry and NOT mix Viagra and nitrates.

Identifying a nitrate these days is far from simple. There are over 20 prescription forms of nitrate drugs. Given so many, it is nearly impossible to remember all of them.

Here is a list of some of the nitrate drugs to which you may refer. (In this list, the chemical name of drug is in bold lower case letters and the corresponding brand names are in capital letters).

Nitroglycerin
Deponit (transdermal)
Minitran
Nitrek
Nitro-BID (and Nitro-BID ointment)
Nitrodisc
Nitro-DUR
Nitrogard
Nitroglyn
Nitrolingual (spray)
Nitrol ointment (APPLI-KIT)
Nitrong
Nitro-Par Nitrostat
Nitro-Time
Transderm-Nitro

Isosorbide mononitrate
Imdur
Ismo
Monoket (tablets)

Isosorbide dinitrate
Dilatrate-SR
Isordil
Sorbitrate

Erythatyl tetranitrate

Pentaerythritol tetranitrate

Sodium nitroprusside

Viagra also causes an additional reduction in blood pressure when administered with amlodipine (Norvasc, Lotrel), a calcium channel blocking drug used to treat high blood pressure and angina pectoris.