The impotence drug Viagra helped to save the life of a premature baby, British doctors say.

When Lewis Goodfellow was born at 24 weeks in August 2006, he weighed just one pound eight ounces. One of his lungs had failed and not enough oxygen was getting to his bloodstream.

His parents started to plan Lewis's funeral.

In a last-ditch effort to save his life, doctors at Newcastle's Royal Victoria Infirmary gave the three-week-old infant sildenafil, sold as Viagra.

Viagra was originally developed to treat angina by relaxing blood vessels and arteries. In sexually aroused men, it helps sustain an erection.

The drug is also being tested to treat children with narrow lung arteries. In Lewis's case, Viagra helped to open the tiny blood vessels in his lungs, allowing them to supply more oxygen around his body.

The boy's mother, Jade Goodfellow, recalled that doctors said they couldn't give him any more oxygen and that they were using Viagra was an experimental treatment that may not have any effect.

The drug worked, and Lewis was allowed to go home in January, but he still needs oxygen around the clock.

Viagra has been used to treat six premature babies, doctors at the hospital say.