A NORTH-EAST woman who was told she needed a heart and lung transplant has been saved - by daily doses of sex drug Viagra.

Until now, Viagra has been better known as a treatment of erectile dysfunction in men.

But scientists have demonstrated that the same properties that increase blood flow to the male genitals can help save the lives of female heart patients by opening up constricted blood vessels between the heart and the lungs.

Two years ago, Leah Halstead, 32, from Darlington, was told she had less than 18 months to live, and her only hope of survival was a heart and lung transplant.

She became gravely ill with pulmonary arterial hypertension, or PAH, a rare condition that affects about 4,000 people in the UK at any one time.

PAH mainly affects women in their 30s and 40s and often leads to premature death within three years.

When she was told she would need a transplant, she was so weak she could hardly stand up or walk more than a few steps.

But within days of being given Viagra as part of a clinical trial involving the Freeman Hospital, in Newcastle, she was amazed at the difference it made.

Mrs Halstead said: "Within a few days, I could walk about and climb stairs without getting severely short of breath.

"I used to need oxygen, but I have not used it since and that was two years ago."

She can now live a more normal life at home with her husband, Billy.

She added: "It has made such a difference. I just hope it keeps working then I don't need to have a transplant."

Mrs Halstead took particular pleasure in cancelling a stairlift due to be installed at her home and telling the company she no longer needed it.

"Exercise or exertion still tires me, but I can go up and down stairs and sometimes we take the dogs for a walk on the beach at Saltburn," said Mrs Halstead.

The manufacturers of Viagra, Pfizer, today unveiled Revatio as a new Viagra treatment for pulmonary arterial hypertension.

After six years of trials, it was proven that treatment with Revatio led to significant improvements. Essentially, the drug is keeping patients alive who would otherwise need transplants.

Revatio is now available for use by hospital specialists. Until now, it is has only been available to patients involved in clinical trials or on compassionate grounds.

Professor Paul Corris, who heads the department of thoracic medicine at Newcastle University, was impressed at the impact Revatio had on his patients, including Mrs Halstead.

"In clinical trials, it has been shown to improve the quality and quantity of patients' lives," he said.

He said Mrs Halstead's condition had been "very severe" and she was now significantly better thanks to the new drug.