Small study finds impotence drugs improved blood flow to muscles in boys with the progressive disease
WebMD News from HealthDay
By Steven Reinberg
HealthDay Reporter
WEDNESDAY, May 7, 2014 (HealthDay News) -- Drugs normally prescribed to treat erectile dysfunction in adult males may help boys who have a muscle disease called Duchenne muscular dystrophy, according to a new study.
In the small study including just 10 boys with the disease, researchers found that the popular drugs Viagra and Cialis improved blood flow to the boys' weakened muscles.
"Boys with Duchenne muscular dystrophy have a blood flow abnormality -- delivery of blood and oxygen to their muscles -- that does not increase the way it should during mild exercise," said lead researcher Dr. Ronald Victor, the associate director of the Cedars-Sinai Heart Institute in Los Angeles.
Because the blood vessels do not enlarge in a normal way in Duchenne muscular dystrophy, muscles are starved for oxygen, according to Victor. Cialis and Viagra work by enlarging blood vessels, thus increasing blood flow, which is the same way these drugs help men with erectile dysfunction.
The report was published online May 7 in the journal Neurology.
Duchenne muscular dystrophy is a genetic disease that affects boys and young men. It causes a progressive loss of muscle function to the point where those who have the disease end up in a wheelchair. The disorder causes the body to produce little or no dystrophin, a protein needed to make the chemical nitric oxide. Nitric oxide signals blood vessels to relax during exercise, increasing blood flow.
Until recently, boys with Duchenne often didn't live much beyond their teens, according to the Muscular Dystrophy Association. Advances in care have increased survival for many of those with the disease into their 30s. There are even some who have lived into their 40s and 50s.
Current treatments, such as steroids, can slow muscle degeneration and protect heart and lung function, but they don't correct the abnormal blood flow, according to Victor. And, more than a quarter of patients cannot tolerate steroids or their side effects, the researchers noted.
For the new study, Victor's team compared 10 boys with Duchenne muscular dystrophy, aged 8 to 13, who were taking steroids, with 10 healthy boys of the same ages.
All of the boys with muscular dystrophy could still walk, but some also used a wheelchair or a scooter.
The researchers measured the blood flow in all the boys when they were at rest and when they were doing a handgrip exercise. The tests showed that the boys with Duchenne had abnormal blood flow, even though they were taking steroids.
After giving Cialis or Viagra to the boys with Duchenne, the tests were repeated. After two weeks, the boys who received Cialis were given Viagra and those given Viagra were given Cialis, then all were retested.
source : Viagra, Cialis May Help Duchenne Muscular Dystrophy Patients
