NEW YORK (Reuters) -- There's more good news for men suffering from impotence -- two experimental drugs that can be taken orally look like promising alternatives to Viagra for the treatment of erectile dysfunction, according to results presented Tuesday at the American Urological Association meeting in San Diego, California.
The bad news is that one study found that a currently available drug, alprostadil (Muse), didn't work as well as expected in clinical practice.
In a study of an experimental drug called phentolamine or Vasomax, about 37% of men with mild to moderate impotence responded to a 40 milligram dose and 45% responded to an 80 milligram dose. In comparison, 16% of men taking an inactive medication (placebo) had a response, reported Dr. Irwin Goldstein, a professor of surgery at Boston University School of Medicine. The major side effect of the drug was nasal congestion. Unlike Viagra, phentolamine could safely be used by men taking nitrates -- such as nitroglycerin -- for heart disease.
"We hope to help a lot of impotent patients with this medication," said Goldstein. The drug will be available in the US in a year or so, Goldstein estimated.
Another impotence drug, apomorphine, is designed to be taken sublingually -- under the tongue. In a study of 457 patients, 60% of men taking a 6 milligram dose of the drug achieved an erection firm enough for intercourse compared with 34% of those taking a placebo, reported Dr. Harin Padma-Nathan of the University of Southern California Medical School.
"The most common adverse event was nausea, which was mild in most cases and was associated with a high degree of habituation -- people got used to it," he said. "Apomorphine sublingually is effective and well tolerated as a potential treatment for MED (male erectile dysfunction) associated with no major organic (physical) component. Studies are currently underway to examine the efficacy and safety of this drug with organic MED including diabetes and spinal cord injury."
A third study found that another impotence drug, alprostadil, did not function as well as expected. In a study of 115 men being treated for impotence, about 27% achieved an erection sufficient for intercourse when given the drug transurethrally (via a suppository placed in the urethra), reported Dr. Pat Fulgham, of Presbyterian Hospital of Dallas in Texas. A clinical trial of the drug had suggested that 66% might achieve an erection.
Overall, only 19% of the men continued to use the drug to treat their impotence, Fulgham reported.
