Viagra could treat Duchenne muscular dystrophy

A group of American scientists have found that drugs normally used for male impotence, such as Viagra and Cialis, could be used to fight Duchenne muscular dystrophy (DMD).

Researchers at the Cedars-Sinai Institute in Los Angeles found that the treatment helped improve blood flow to the muscles of boys suffering with DMD, which they hope will slow the disease's progress to breakdown muscle fibres. 

The condition affects one in every 3,500 newborn boys and causes many sufferers to die before the age of 30 as the disease can affect the muscles necessary to breathe and pump blood around the body. Many boys with the disease are reliant on a wheelchair by ten as there is no effective treatment for the condition.

During the study, the team of researchers tested the new drugs with ten boys suffering with DMD between eight and 13 years old with blood flow problems. They were all given one dose of sildenafil (Viagra) or tadalafil (Cialis), which are commonly used to treat erectile dysfunction.

The scientists then measured blood flow in the boys' muscles when they were resting and while they were doing handgrip exercise. This data was then compared to ten boys of the same age who did not have the condition.

According to the study, after a single dose of either drug, the boys' muscle returned to a healthy level.

The research could be a significant breakthrough for boys suffering with DFD as the current treatment is ineffective. Corticosteroids, currently used for short-term treatment, has a range of side effects and does not work in a quarter of all patients.

"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 and associate director at the Cedars-Sinai Heart Institute. 

The study, published in the Neurology journal, could pave the way for a much larger study to confirm the results and to determine whether this treatment can prevent or at least slow the degeneration associated with DMD, according to Dr Victor.