Tuesday, December 7, 2010

Viagra

For the drug that flopped in clinical trials, Viagra has subsequently been an extraordinary success story. When scientists first concocted the little blue pill more than 20 years ago, it was as a treatment for the heart condition angina.



The idea was that it would ease pain by dilating blood vessels around the heart.
The results were disappointing, until doctors noticed an extraordinary side-effect among male volunteers.



"Researchers knew they were on to something when patients refused to give the drugs back at the end of the trial," says Dr Mike Kirby, adviser to the Sexual Dysfunction Association.
Viagra generates sales of more than £1 billion a year and, as well as providing effective treatment for erectile dysfunction, is attracting interest as a potential remedy for a range of other illnesses from deadly lung disorders to cold hands.



The secret of Viagra, and other drugs in the same class, is that they allow blood to flow more freely by helping arteries to relax. They do this by blocking the effects of an enzyme called phosphodiesterase.



Evidence suggests it could even be used to combat jet lag.
Below, we examine other ways the modern day wonder-drug could help repair the damaged body. In most cases, research is still at an early stage and the drug is not yet being widely used. In others, such as the deadly lung disease pulmonary arterial hypertension, a form of the drug is already being used to save lives in Britain.



HEART ATTACKS
Giving Viagra after a heart attack could repair damaged muscle by restoring oxygen supplies. Researchers at Virginia Commonwealth University in the U.S. compared the antiimpotence drug with nitroglycerin, the standard treatment given to heart attack victims, and found Viagra was better at restoring bloodflow and helping tissue heal.



BREAST CANCER
Breast and colon tumours in mice shrank threefold when they were injected with the drug in experiments at Johns Hopkins University in the U.S. Scientists believe Viagra works by 'unmasking' cancer cells, so the immune system can recognise them as foreign and destroy them.



COLD HANDS
Raynaud's disease affects up to one in five people and is caused when blood supply to fingers and toes is interrupted. Most of the time they appear cold, white and look dead, but exposure to cold can trigger a burning sensation. Patients given 50mg of Viagra twice a day, for four weeks, had fewer and much shorter 'burning' attacks due to better bloodflow.



CROHN'S DISEASE
British researchers claim the sex pill could fight Crohn's disease, a debilitating condition, which often needs major surgery on the bowel. Tests at University College London showed the drug boosts bloodflow around the small intestine - the area most affected by the disease - and helps fight bacteria.



INFERTILITY
A woman's chances of becoming pregnant could improve, according to scientists. In some women, the lining of the uterus is too thin to sustain a pregnancy. The drug increases bloodflow to the uterus and stimulates growth of cells.



DIABETES
Three out of four diabetics suffer gastroparesis - when the stomach empties too slowly. It causes loss of appetite and dehydration. U.S. scientists found Viagra helped by relaxing stomach muscles.



PELVIC PAIN
Up to 50 per cent of men suffer pelvic pain, causing discomfort around the lower back and groin.
Viagra appears to help by dilating blood vessels in the pelvic area and boosting bloodflow, according to a trial at Washington University in the U.S..



STILL BIRTHS
Every year, about 600 babies in the UK are stillborn because of a pregnancy disorder called pre-eclampsia. But foetal deaths dropped sharply in pregnant mice given the Viagra. In pre-eclampsia, arteries feeding the placenta do not widen enough to deliver all the blood the baby needs. Viagra relaxes muscles in the artery walls.



LUNG DISEASE
Nobody knows what causes pulmonary arterial hypertension, a condition that affects about 4,000 people in the UK, often women in their 30s and 40s. But few sufferers survive beyond three to four years. Blood pressure becomes dangerously high in the pulmonary artery. A Viagra-based drug called Revatio is extending the lives of some sufferers by boosting blood flow to the lungs, reducing the workload on the heart.



PROSTATE PROBLEMS
The little blue pill can improve symptoms of benign prostatic hyperplasia. BPH is part of the natural ageing process and nothing to do with prostate cancer. But it does cause frequent urinating, bladder stones, depression and daytime tiredness due to constant broken sleep. Doctors at Northwestern University in Chicago tested the drug on 300 men - it had a good effect..

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