FDA Approves Viagra For Impotence
NEW YORK, NY — March 27, 1998 — The United States Food and Drug Administration has approved Pfizer Inc.’s breakthrough oral therapy Viagra (sildenafil citrate) for the treatment of erectile dysfunction.
Taken about an hour before anticipated sexual activity, Viagra is a tablet that works naturally with sexual stimulation. Viagra is effective in most men with erectile dysfunction (ED), the medical term for impotence, which is associated with a broad range of physical or psychological medical conditions.
Viagra is the first in a new class of medications known as phosphodiesterase type 5 inhibitors that improve blood flow to the penis. In clinical trials, Viagra has been demonstrated to restore sexual function in most patients.
Erectile dysfunction is defined as the consistent inability to achieve and/or maintain an erection sufficient for satisfactory sexual activity. An estimated 30 million men in the U.S. are affected by ED, according to the medical literature. The prevalence of ED increases with age.
Viagra was tested in more than 4,000 men. In 21 clinical trials, which included men with ED that was diagnosed as mild, moderate or complete, the median age of patients was 55. They had a broad range of conditions associated with ED including high blood pressure, high cholesterol levels, diabetes and prostate surgery. Patients had experienced ED for an average of five years prior to entering the clinical trials.
Viagra was shown to be effective in approximately seven out of 10 men overall and was effective across patients with ED attributed to diabetes, spinal cord injury, or psychological causes, among others. Trial results for patients and partners were assessed using questionnaires designed with leading academic researchers.
Viagra was well tolerated by patients in the clinical trials; drop out rates were 2.5 percent for patients taking Viagra compared to 2.3 percent of patients taking placebo. The most common side effects of Viagra were headache, facial flushing and indigestion. Viagra should not be used by patients taking nitrates in any form, including the heart medicine, nitroglycerin.