Erectile Dysfunction Drugs Could Treat Muscular Dystrophy
Duchenne muscular dystrophy is a genetic disorder that causes muscle weakness, which progresses quickly. Many boys who have the disease do not live past 30-years-old. In a new but small study, researchers examined the potential effects of using erectile dysfunction drugs, such as Viagra or Cialis, in treating boys diagnosed with this condition. They concluded that the drugs were able to increase blood flow to the body's 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 reported by Philly.
For this study, the researchers recruited 10 boys with Duchenne muscular dystrophy and 10 boys without the condition, all between the ages of eight and 13. The researchers tested the boys' blood flow and handgrip strength. They found that even though the boys with Duchenne muscular dystrophy were on steroid treatment, the tests results revealed abnormal blood flow.
The team only tested the effects of these drugs on the boys with the condition. Some of the boys took Viagra while the rest took Cialis for two weeks. The team tested their blood flow and handgrip. The medications were then switched for another two weeks. All 10 boys were retested at the end of this part of the study.
"A few boys in our study had erections after taking these drugs," Victor said. "The erections were not painful and not dangerous and resolved spontaneously without treatment."
The researchers found that Viagra and Cialis were capable of improving blood flow in the boys. The blood flow ended up being equal to the blood flow measured in the healthy boys.
"The findings in this small study led to a large clinical trial, which is enrolling now in the U.S. and abroad, to see if 48 weeks of treatment with once-daily Cialis will slow the decline in walking ability in 7- to 14-year-old boys with Duchenne," Victor said. "The findings offer some hope, but we need to wait for the results of the large treatment trial to see if daily treatment with Cialis has a clinically meaningful benefit for boys with this form of muscular dystrophy."
Despite the study's findings that these drugs could help with blood flow, the researchers could not conclude that Viagra and Cialis helped improve the boys' ability to walk. There was also no evidence that the drugs helped slow down or stop the progression of the disease. The study was published in Neurology.