In recent trials, the drug alprostadil helped 12 of 31 men with moderate to severe impotence when applied in gel form on the penis. Many of the men could only achieve an erection by injecting one or more drugs into their penises.
The active ingredient in the gel is alprostadil, or prostaglandin E1, a chemical found in humans and other animals that dilates blood vessels. The new gel contains an additional ingredient, called SEPA, which temporarily makes the outer layer of skin more permeable.
The drug is currently available as an injection or penile suppository, but the new method of applying it gets rid of the pain caused by the other methods. It hasn't worked for topical application until now because it could not be absorbed through the skin.
The only side effect reported in the Boston study of the topical gel was a mild sensation of warmth, said officials from MacroChem Corp., a Lexington-based company that is developing the gel. Company officials said the mild side effects were due to the fact that the gel was applied only to the glans, or head of the penis, while in an earlier study, the substance was applied to the penile shaft.
Using the gel would not enhance sexual performance in men who do not suffer from impotence, said Dr. Irwin Goldstein, a Boston University urologist.
A larger study will be conducted on men who try either the gel or a placebo at home. After the larger studies are completed, the drug must still receive federal approval, a process that could take several years.
Reported By Dr. Emily Senay