News

1 Nov, 2006

The erectile dysfunction drug Viagra may have found a new, potentially life-saving use in hospital pediatric intensive care units, researchers report.

Australian researchers gave the drug to 15 babies with congenital heart disease who were being weaned from inhaled nitric-oxide therapy, a treatment that ICUs use to help these infants survive.

The researchers found that a dose of Viagra prevented a common life-threatening complication called rebound pulmonary hypertension. They also found that it significantly reduced the amount of time the babies spent on mechanical ventilation and in the ICU.

"Rebound pulmonary hypertension is a very common problem," said Dr. Steven Abman of The Children's Hospital in Denver, who was not part of the study. "This is the most rigorous study that's ever been done to demonstrate that Viagra can prevent this complication."

The study results were published in the November issue of the American Journal of Respiratory and Critical Care Medicine.

Viagra is useful for treating both erectile dysfunction and preventing rebound pulmonary hypertension because it affects pathways involved in both conditions.

"Viagra enhances the body's levels of cyclic-GMP, a naturally occurring substance that relaxes arteries and reduces their pressure, which is why its primary indication is for men with erectile dysfunction," explained the study's lead researcher, Dr. Lara Shekerdemian of the Pediatric Intensive Care Unit at the Royal Children's Hospital in Melbourne.

"However, cyclic-GMP is abundant in the lungs and is the molecule via which nitric oxide acts as a dilator of pulmonary arteries," Shekerdemian said. "That's why its use was explored in the setting of pulmonary hypertension in the newborn."

In the study, Shekerdemian and colleagues gave a single dose of Viagra to 15 infants with congenital heart disease who were undergoing withdrawal from nitric oxide, which is used to relax pulmonary blood vessels in mechanically ventilated lungs. Another 14 infants undergoing withdrawal were given placebo.

None of the Viagra-treated infants developed rebound pulmonary hypertension compared to 10 of the placebo-treated infants. After more than 24 hours, all of the infants who developed rebound hypertension were given Viagra during a subsequent and successful attempt to wean them from nitric oxide.

The Viagra-treated infants also spent less total time on a mechanical ventilator than the placebo-treated infants -- a little over 28 hours compared to 98 hours -- and had a considerably shorter stay in the intensive care unit (47.8 hours vs. 189 hours).

"Although we expected to see an avoidance of rebound, we were not expecting to see these additional benefits," Shekerdemian said. "Any intervention that smoothes their course in the intensive-care unit would have at least a short-term positive influence on their recovery from their underlying condition."

Unless there's some reason for not using Viagra, Shekerdemian said that it should be routinely used as infants are weaned from nitric oxide. "We certainly do so now in our pediatric intensive-care unit," she said.

Many hospitals are already doing just that. "I think it already has become standard clinical practice, because the idea of using Viagra for this is not new," Abman said. "What's new is that this is the first study to look at it with a nice protocol in which they randomized patients and controlled in a blinded way. So it verifies what we've already been doing in clinical practice."

Shekerdemian and her team are now conducting a similar study in the Royal Children's Hospital's Neonatal Intensive-Care Unit to see if Viagra can prevent rebound pulmonary hypertension in premature infants.

http://www.nlm.nih.gov/medlineplus/news/fullstory_40844.html

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