Viagra: Wonderful But...

Viagra has been hailed as a wonder drug by many users, but its maker, Pfizer Inc., cautions that there are circumstances in which it should not be used.

The company says it should never be used by anyone taking a nitrate drug such as nitroglycerin because this could cause a dangerous drop in blood pressure.

It also advises that Viagra should be used with caution in men who've recently had a heart attack or stroke or who have very high blood pressure, sickle-cell anemia, leukemia, active peptic ulcers or the retina condition, retinitis pigmentosa.

Viagra will not help men who have suffered the loss of the nerves needed for an erection—as, for example, through prostate cancer surgery. Today, however, specially trained urological surgeons are able to preserve those nerves in many prostate cancer patients by using a new nerve-sparing technique pioneered by Patrick Walsh, M.D., of Johns Hopkins University.

Currently being studied in Phase III trials—the final step before submitting a drug for Food and Drug Administration approval—is a new drug called Vasomax (phentolamine), which may be safer for men with heart problems than Viagra. Initial findings seem to indicate, among other things, that Vasomax does not interact with nitrate heart drugs.