The pill, approved today by the Food and Drug Administration, will be available only by prescription. The FDA said Viagra, known chemically as sildenafil, appeared to cause few side effects. It works by blocking an enzyme found mainly in the penis. That enzyme is responsible for quelling an erection after sex by breaking down a chemical called cyclic GMP that is produced during sexual stimulation. Hard Side Effects Impotence is highly treatable, but until today the options all had drawbacks.
Penile implants require surgery.
Injecting drugs into the penis can be painful and sometimes causes hours-long erections. Men are squeamish about the suppository Muse, a tiny medicated pellet that is pushed into the end of the penis with a slender plunger. In studies of several thousand men, researchers reported that Viagra helped over 70 percent improve their erections. Copyright 1998 Associated Press. All rights reserved.