Impotence Drugs in the Spotlight -- for Different Reasons
WebMD News Archive
"The nitrate studies are very small with Uprima. There's about a 10%
incidence of blood pressure changes. They're not of the magnitude that occur
with Viagra and nitrates, but they are somewhat concerning," John Mulhall,
MD, assistant professor of urology at Loyola University Medical Center, tells
There also are questions about Uprima's effectiveness since a relatively
high percentage of those getting placebo treatments also were able to achieve
an erection. "The patients that were entered into the study may not have
had severe sexual dysfunction to start out with," says Patrick Walsh, MD,
chief of urology at Johns Hopkins Medical Institutions in Baltimore.
Uprima is thought to work by stimulating that area of the brain responsible
for causing erections. Interestingly, it's also been used to treat Parkinson's
Now a new study suggests that Viagra may prove beneficial to people with
Parkinson's disease. Symptoms of Parkinson's include shaking, poor balance,
muscle rigidity, and dyskinesia, or abnormal, involuntary muscle movements.
In this study, presented at a neurology conference in San Diego, seven of
nine Parkinson's patients treated with Viagra experienced a significant
improvement in dyskinesia, with three patients reporting a complete resolution.
The benefits lasted for as long as they remained on the drug and returned when
the drug was discontinued. The patients continued taking their other medicines
while on Viagra and experienced no worsening of their symptoms. Flushing of the
face, reported by one person, was the only side effect, and there was no change
in sexual function.
Neurologist David M. Swope, MD, who conducted the trial, tells WebMD he was
intrigued when one of his patients, a 60-year-old man, said his Parkinson's
symptoms improved after he started taking Viagra for impotence. Swope theorizes
that the drug's effects may resemble those of dopamine, a chemical in the brain
and nervous system known to be decreased in Parkinson's patients. Swope is
assistant professor of neurology at Loma Linda University in Loma Linda,
"I was surprised it worked in these patients as well as it did," he
says. "I ? wasn't expecting it to be effective in these patients."
Swope warns that these findings are "very, very preliminary. We need more
evidence that it actually works before it is used routinely." He is now
designing another study to test the effects of Viagra more carefully. "I
think [the role of Viagra] has yet to be defined, but potentially this might be
a new approach to treatment."