Viagra: A New Treatment For Erectile Dysfunction

James Metz, MD
Abramson Cancer Center of the University of Pennsylvania
Last Modified: November 1, 2001

The Food and Drug Administration recently approved Viagra (sildenafil citrate), the first oral pill to treat impotence. Viagra affects the response to sexual stimulation by enhancing the smooth muscle relaxant effects of nitric oxide. This allows increased blood flow into certain areas of the penis leading to an erection.

Viagra was evaluated in numerous randomized, placebo controlled trials involving 3700 men with various degrees of impotence associated with spinal cord injury, history of prostate surgery, diabetes, and no identifiable cause of organic impotence. In all pre-approval trials, men on Viagra reported success more often than did men on placebo, and the rates of success increased with dose. Across all trials, Viagra improved the erections of 43% of radical prostatectomy patients compared to 15% on placebo.

Viagra is only available by prescription from your physician The recommended dose is 50 mg taken 1 hour before sexual activity. The dose may be adjusted by a physician depending on the patient's response. The drug should not be taken more than once a day. Viagra has no effect in the absence of sexual stimulation.

There are some precautions and contraindications to the use of Viagra. Men who have conditions that may cause sustained erections (priapism) such as sickle cell anemia, leukemia, or multiple myeloma should not take Viagra. The drug should not be used in combination with organic nitrates such as nitroglycerin patches or tabs placed under the tongue because the combination may lower blood pressure. Also those patients who have Peyronie?s disease may need to take Viagra with caution. As with any medication, Viagra can interact with other prescription and over the counter medications. Anyone considering Viagra should discuss all of their medications with their physician. Viagra has not been studied in combination with other treatments for erectile dysfunction so its use in combination with these other methods is not recommended.

Viagra seems to be well tolerated with the most common side effects including headache, flushing and indigestion. Some patients report changes in vision, principally color perception. As with any new medication, more side effects may be reported with the increased use of the medication.

After various forms of cancer treatment, many men have difficulty getting or maintaining erections. Surgery and radiation therapy to the pelvic area, hormonal therapy, chemotherapy, and medications may all significantly impact a man's ability to obtain erections. Erectile dysfunction can cause significant anxiety for the man and his partner. There are many treatments available for erectile dysfunction in the cancer patient. Viagra may be a viable treatment for some patients, but this needs to be determined on an individual basis.