VIAGRA: BEYOND THE JOKES
Title: VIAGRA: BEYOND THE JOKES , Harvard Heart Letter, 10515313, Oct98, Vol. 9, Issue 2
For months now, Viagra has been a source of intense interest and an endless supply of jokes. The fact is that this pill can help as many as 69% of men with impotence achieve erections sufficient for sexual intercourse. This medication seems destined to be among the most commonly used drugs in this country. Its availability is creating interesting social issues as sexual lives are renewed for many men in their 60s, 70s, and beyond — and for their companions.
Since impotence is common among people with heart disease, Viagra is a particularly important topic for readers of the Harvard Heart Letter. And while the risks of serious complications from this drug are actually very low, people with heart disease are the ones who are most vulnerable to these side effects. What follows is a primer on the special concerns about Viagra for people with cardiovascular conditions.
The Silent Epidemic
impotence is so prevalent among men with heart disease that all too often it is accepted as “just the way things are going to be.” The most common diseases that cause impotence are atherosclerosis and diabetes. Just as atherosclerosis can block blood vessels in the heart, it also can impede blood flow to the penis, thereby weakening or preventing erections. Diabetes is, of course, an important risk factor for atherosclerosis, but it also can contribute to impotence by damaging nerves in the penis. Some data suggest that half of male diabetics have problems with impotence .
Even if these disease processes themselves do not cause impotence , many of the medications used to treat heart disease might. Two classes of drugs that can cause impotence are beta blockers (such as atenolol, propranolol, and metoprolol) and diuretics, such as hydrochlorothiazide.
Of course, sex requires more than just having functioning equipment. Many experts believe that an absent or reduced sex drive (libido) is the greatest contributor to sexual problems for heart-disease patients. Depression is quite common among people struggling to live with a heart condition, and this mood change often lowers interest in sex. Even if libido returns to “normal” as patients adjust to their condition, some couples may have difficulty resuming their sexual relationship because the patient or spouse fears that doing so may trigger a heart attack.
In an ideal world, men with impotence would undergo a medical evaluation to determine what, if any, conditions (for example, diabetes) might be contributing to this problem. Their physicians would review all medications and determine whether altering these regimens might correct the problem. Finally, a frank discussion about the patient’s and spouse’s fears would take place and most likely relieve many of those concerns.
Unfortunately, this ideal scenario occurs all too rarely. Because so many men are understandably reluctant to talk about this private problem, impotence remains a silent epidemic. Perhaps one of the best “side effects” of Viagra is that it will encourage men to discuss impotence with their doctors, probably for the first time.
Amplified Signals
Of course, Viagra does more than lead patients to their doctors. This drug blocks an enzyme that breaks down a chemical called cyclic GMP that helps the penis fill with blood. Higher levels of this enzyme can help initiate and maintain an erection.
However, Viagra cannot do all the work itself. Sexual stimulation is needed to trigger this chain of events. Such stimulation leads to neurological signals that cause cells in the penis to generate cyclic GMP in the first place.
Men should take Viagra one hour before the expected time of intercourse. Viagra is available in 25-mg, 50-mg, and 100-mg tablets. Most physicians start men on the 50-mg tablets and increase the dosage to 100-mg if necessary. For some, the 25-mg dosage is effective.
Sex and Death
Ironically, Viagra was initially developed and tested as a treatment for coronary artery disease. While it did not do much for heart disease, it did improve sexual function in many men participating in the trial. Such reports rescued the drug from oblivion. Viagra underwent extensive testing before the U.S. Food and Drug Administration approved it as a treatment for impotence . How, then, could it be dangerous for people with heart disease?
The primary reason is that many people with coronary artery disease use various forms of nitroglycerin and other medications that fall into the category of “nitrates.” Viagra and nitrates have some similar effects and when used together can lead to profound drops in blood pressure. Drugs in the nitrate category include long-acting preparations used to prevent angina (including Imdur, Ismo, Sorbitrate, and Isordil) and the small nitroglycerin tablets that people commonly put under their tongues during episodes of chest pain. Finally, this class of drugs also includes substances that are abused by some people as sexual stimulants (for example, amyl nitrate).
Accordingly, Pfizer (the manufacturer of Viagra) and physicians have emphasized repeatedly and emphatically that these drugs should never be used together. Still, several deaths have occurred among men who have used Viagra and nitrates.
Another scenario involved men who did not know they had heart disease (and therefore were not using nitrates) and who developed angina or heart attacks during sex made possible by Viagra. In some cases, physicians treating these men were unable to administer nitroglycerin because of the presence of Viagra. Alternatively, some doctors, unaware that the patients had taken Viagra, administered nitroglycerin with disastrous effects.
The cardiovascular effects of Viagra suggest that there may at least be a potentially small increase in risk of this drug for patients who:
have coronary ischemia, even if they are not taking nitrates
have congestive heart failure and borderline low blood pressure
take several medications for high blood pressure
take other medications such as erythromycin or cimetidine or who have other conditions (such as liver or kidney disease) that might prolong the half-life of this drug
Finally, some of these deaths almost surely occur because many elderly men are undergoing the physical and emotional stress of sex for the first time in many years. In general, the stress of sex does not pose major risks for people with heart disease. However, there are not many “rigorous” studies of this topic. Does Viagra make sex more dangerous for elderly men? It is difficult to know in the absence of information on the risk of death for these men if they were not having sex or the risk of death if they had sex without Viagra.
No Joking Matter
It is true that men who take Viagra may have a slight increase in heart-attack risk during sex. But this possibility does not mean that Viagra is a bad drug. In fact, it is a very good drug that is improving the quality of life for many couples.
Nevertheless, men with known heart disease should use this drug with caution. Men who experience symptoms suggestive of a heart attack, such as chest pain or pressure, should seek medical attention promptly and be certain to alert physicians that they have used Viagra. And no one should combine nitrates with Viagra. Ever!
There are not yet data on the benefits of this drug except in men with impotence . Individuals without a diagnosis of medical impotence should not use Viagra. Any possibility that Viagra might enhance sexual experiences for women or for men without impotence is offset by the small but real risk of complications.
Finally, whether or not they decide to try Viagra, men with impotence should openly talk about this problem with their physicians. That discussion alone may improve care of the medical problems that can contribute to the sexual dysfunction.
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Source: Harvard Heart Letter, Oct98, Vol. 9 Issue 2, p1, 3p
