The two leading organizations for U.S. cardiologists have issued preliminary recommendations for the use of Viagra. At press time, final approval of these recommendations from the leadership of the American College of Cardiology and American Heart Association was slated for December 1998. These guidelines include cautions that go beyond avoiding the combination of Viagra and nitrate-containing medications (such as nitroglycerin).

The American College of Cardiology/American Heart Association guidelines suggest that Viagra may be hazardous for patients with certain medical profiles and urge caution when physicians consider prescribing Viagra for the following types of patients:

I. Those with active coronary ischemia, whether or not they are taking nitrates to control their symptoms of angina. Even if these patients are not using nitrates, the possibility that they might develop angina after sexual intercourse and need nitroglycerin therapy makes use of Viagra risky. Any patient who develops symptoms of angina after using Viagra should avoid taking any nitrates for 24 hours.

II. Individuals with congestive heart failure and borderline low blood pressure. In these patients, Viagra could cause a dangerous drop in blood pressure even if they are not using nitrate medications.

III. Patients on a complicated multi-drug program for their blood pressure.

The concern is that their medications may interact with Viagra to cause large drops in blood pressure.

IV. People taking certain drugs (examples include erythromycin or cimetidine) or who have conditions, such as liver or kidney disease, that can slow the body's removal of Viagra. In these patients, Viagra may last longer, prolonging the danger period if complications arise.

Because of the danger of life-threatening falls in blood pressure, the guidelines also urge avoiding the combination of these medications for 24 hours after the use of Viagra.

These warnings do not mean that Viagra is a dangerous drug that should not be used - it has improved quality of life for many men with impotence.