WEDNESDAY, -- Viagra doesn't create any special cardiovascular risk, even for men whose seriously narrowed arteries require treatment, says a new study funded by the drug's manufacturer.
The only danger is that the sexual activity made possible by Viagra may put an unexpected strain on hearts of men unaccustomed to physical exertion, says Dr. Howard C. Herrmann, professor of medicine at the University of Pennsylvania Medical Center. However, men taking nitroglycerin or its chemical relatives for heart disease are at risk from the drug, Herrmann says.
The conclusions are based on a detailed examination of Viagra's effect on 14 men referred to the medical center for angioplasty, a procedure to reopen dangerously narrowed blood vessels.
"No adverse cardiovascular effects of oral sildenafil [Viagra's generic name] were detected in men with severe coronary artery disease," says a report on the study in the June 1 New England Journal of Medicine.
The study was prompted by continuing worries that Viagra might be behind the deaths of some men who took the drug for erectile dysfunction, also known as impotence, Herrmann says. For example, last March physicians at Cedars-Sinai Medical Center in Los Angeles reported finding 522 fatalities, mostly from cardiovascular problems, among 1,473 adverse events involving Viagra reported to the Food and Drug Administration.
Herrmann's study was funded by Pfizer, Inc., which sells Viagra, though he says, "The study was conceived by me. Pfizer agreed to fund it and had nothing else to do with it." Herrmann says he owns no stock in Pfizer and has no financial stake in the outcome of the study.
Minor drop in blood pressure
The average age of men in the study was 61. Nearly half had diabetes and more than half had high blood pressure and were smokers -- all major risk factors for cardiovascular disease. The Pennsylvania doctors measured their blood pressure and blood flow in the lungs, heart and the whole body, gave them Viagra, then did the same measurements again.
Not much changed after the drug was given, except for small decreases in blood pressure in the arteries and the lung, the researchers say. The results support the position of the American Heart Association and the American College of Cardiology that Viagra is safe for men with some degree of coronary artery disease, as long as they are not taking a nitrate drug, which is known to interact dangerously with Viagra, Herrmann says.
The study gives more evidence that "Viagra probably causes no direct risk of causing a cardiovascular event that we have been able to discern," says Dr. Richard Stein, chief of cardiology at the Brooklyn Hospital Center and a spokesman for the American Heart Association.
Any risk "is trivial compared to the other things you do. Unless you limit your life so that you never do even moderate exercise, why would you want to give up sex?" says Stein.
Stein says obvious exceptions apply to people with severe heart disease -- those with unstable angina or those in the most severe stages of heart failure. "And if you are taking nitrates to lower blood pressure, Viagra is an absolute no," Stein says.
"If you are worried about the rigors of sexual activity, a stress test can show if there is any risk. If the stress test shows that sexual activity is safe, I would have no qualms in prescribing Viagra." Herrmann says.
He says sex is like any kind of exercise when cardiovascular health is concerned, so "any man with risk factors for heart disease who has been sedentary and is considering an exercise program, I would recommend that person consult a doctor."
What To Do
The study was meticulous, but the small number of patients may leave room for doubt. Anyone with a heart condition who is thinking about Viagra should ask a doctor whether any medications could cause complications.
The National Institute of Diabetes and Digestive and Kidney Diseases has more on impotence.
This study confirms the cautions of American Heart Association about Viagra.
for more about the blue pill, visit the Food and Drug Administration.
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