How Dangerous is Viagra?

When the first effective pill for male impotence reached the marketplace in 1999, the roller-coaster ride began. First, there was the predictable rash of jokes and publicity for the pill, known as Viagra. Then came surging sales as many of the 30 million men who have what is known medically as "erectile dysfunction" sought prescriptions from their doctors (or over the Internet). Shortly thereafter came the first reports of deaths (from heart attack or cardiac arrest) of men who had just used Viagra.

Many of these deaths occurred among men who had somehow overlooked the strong warnings from the drug's manufacturer (Pfizer, Inc.) stating that Viagra must not be combined with nitroglycerin. These tragedies followed a typical scenario: a man takes Viagra, gets chest pain, and takes nitroglycerin to relieve his symptoms. Combining Viagra and nitroglycerin can produce a life-threatening drop in blood pressure that is very difficult to reverse. In some cases, patients were given nitroglycerin in hospital emergency rooms because they were too embarrassed to tell the medical staff that they had recently taken Viagra. But some of these deaths did not involve nitroglycerin. These men took Viagra and died before, during, or after sexual intercourse. Some of these men had known coronary disease; others did not, yet none of them had taken nitroglycerin.

These cases have raised concern and questions. Is Viagra dangerous? Or did these deaths simply reflect the expected death rate among men who have heart disease - diagnosed or undiagnosed? After all, heart attacks occur all the time, and some are going to occur by coincidence just after men have taken pills, whether those pills are Viagra or a daily vitamin.

It isn't surprising that the death rate among men who use Viagra is going to be higher than that among men who have just taken vitamins because the causes of impotence include conditions like diabetes and atherosclerosis. In addition, sexual intercourse requires a fair amount of physical exertion and briefly doubles a man's risk of having a heart attack. If a man who would not otherwise have sex takes Viagra, has sex, and has a heart attack, the heart attack might well have been triggered by the sex - and not by the Viagra.

Relax

Researchers from the University of Pennsylvania recently published reassuring information regarding the association of Viagra with death due to cardiovascular disease. These investigators, writing in the New England Journal of Medicine, described a clever study of the impact of Viagra on blood pressure and blood flow. This small study involved 14 men who had a narrowing of at least one coronary artery, a condition sufficiently severe that each required coronary artery angioplasty to open the vessel.

While these men were in the cardiac catheterization laboratory - with tubes (catheters) actually inserted into their diseased coronary arteries - they took Viagra, and the researchers measured the cardiovascular ...