FDA approves pill to treat impotence

New pill must be taken an hour before sex

Easier, less cumbersome than traditional therapies

March 27, 1998

Web posted at: 7:33 p.m. EST (0033 GMT)

WASHINGTON (CNN) -- Millions of men suffering from impotence will soon have access to a treatment that promises to be less intrusive and easier to use than traditional therapies.

The U.S. Food and Drug Administration gave approval Friday to Viagra, the first pill to treat impotence in men. Tests on 3,000 men showed that Viagra was effective for seven out of 10 patients.

The pill is expected to be in pharmacies in about two weeks, and it will cost $7 a pill.

Viagra is the first non-surgical treatment for impotence that doesn't have to be either injected or inserted directly into the penis. Unlike mechanical devices, it will not cause an erection unless a man is sexually simulated.

"It's an erection enhancer," said Dr. Drogo Montague of the Cleveland Clinic, who says most patients will prefer taking a pill to the other, more cumbersome treatments.

'Drug does not change libido or desire'

Viagra must be taken an hour before sexual activity. The drug enhances the relaxant effect of nitric oxide, a chemical released during sexual stimulation that increases blood flow to the penis, leading to an erection.

The company that makes Viagra, Pfizer Inc., originally created the drug as a heart medicine. It pursued the idea of using it to treat impotence after some heart patients reported having unexpected erections.

But experts cautioned that the drug is only effective in men with sexual dysfunction -- and should not be prescribed as an "aphrodisiac" in healthy men.

"This drug does not change libido or desire ... and it's not going to have any impact on normal men," said Dr. Harin Padma-Nathan of the University of Southern California.

Side effects: headache, upset stomach

The drug does have some side effects. The most common include headaches and upset stomachs.

At high doses, some men developed a temporary visual problem where they could not differentiate between the colors blue and green. It can also only be taken once a day.

The pill may not help everyone. In testing, researchers found that men with diabetes or who had undergone radical prostate surgery were less likely to benefit. The drug also should not be taken with nitroglycerin pills or patches.

But impotence specialists hope the pill will encourage more patients to seek medical help. Only 5 percent of men suffering from impotence, as many as 20 million, now seek treatment. Padma-Nathan predicts that with a pill treatment available, that could jump to 20 percent.

Some pharmaceutical analysts says Viagra could become one of the top-selling drugs of all time, with sales that could reach $500 million by 2003. Half a dozen other pills to treat impotence are expected to be on the market within the next seven years.

Correspondent Dr. Steve Salvatore and Reuters contributed to this report