Viagra 'may cause blindness': Ingredient in the drug can permanently affect sight, doctors warn

Viagra may cause loss of vision in men with retinitis pigmentosa

Retinitis pigmentosa is a rare inherited eye condition causing sight loss 

Some people have normal vision but carry one gene for the condition

Ingredient in Viagra linked to degenration and death of cells in the retina

People with retinitis pigmentosa and those who carry the gene at risk 

Viagra could cause blindness in men with eye problems, and even those with seemingly normal vision, a new study has found.

Australian researchers say an ingredient in anti-impotence drugs may permanently affect the vision of men with an inherited eye condition.

It could also affect those with normal sight who carry one gene which is linked with developing eye problems.

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Viagra could cause blindness in men with inherited eye condition retinitis pigmentosa - or those with normal sight who carry the gene for the condition, Australian researchers have found

One theory is that erectile dysfunction drugs may obstruct an enzyme which is important for transmitting light signals from the retina to the brain.

It is already known that sildenafil, the active ingredient in the erectile dysfunction medication, can cause temporary vision problems in some healthy people.

Doctors have now warned it could also cause permanent damage to the eyes of people retinitis pigmentosa.

People with normal sight that carry the gene for the condition may also be at risk, experts warn.

 

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Retinitis pigmentosa is a rare hereditary condition that causes the cells in the retina - the area of the back of the eye which detects light - to degenerate and die.

This can lead to difficulty seeing in dim light, loss of peripheral vision, and sometimes blindness. 

About one in 50 people are likely to be carriers of genes which lead to the degeneration of cells in the retina.

OTHER PROBLEMS LINKED WITH ANTI-IMPOTENCE DRUGS 

Loss of hearing

In 2011, Viagra and similar impotence drugs were linked to hundreds of cases of sudden hearing loss around the world.

Research published in the journal The Laryngoscope said it was not clear how long the problems lasted, but this type of hearing loss - more commonly due to infections and exposure to loud noise - usually causes permanent damage in up to a third of cases.

Skin cancer

Earlier this year, American researchers found that men who used Viagra were 84 per cent more likely to get melanoma, the most deadly form of skin cancer.

It is thought the impotence drug may affect the same genetic mechanism that enables skin cancer to become more invasive.

In the new study, researchers from the University of New South Wales, Australia,  tested sildenafil on healthy mice and mice with one copy of this mutant gene.

They found the healthy mice experienced problems with their eyes for about two days.

However the drug affected the vision of mice who carried the mutant gene for two weeks.

The researchers also found early signs that the cells in the mice's eyes were dying, suggesting sildenafil may cause loss of vision in people who carry the gene for the disease but have normal vision.

Dr Lisa Nivison-Smith, of the UNSW School of Optometry and Vision Science, said: 'If cells actually die in the retina that would lead to blindness.'

People who have normal vision, but who carry a single copy of the mutant gene for retinitis pigmentosa, could be more susceptible to changes caused by sildenafil, she added. 

The study was published in the journal Experimental Eye Research.The news comes after reports that Britain is braced for a 'Viagra boom' after the drug's patent ran out last year.

The cost plummeted by 93 per cent as cheaper generic versions of the drug became available.  

Previous studies have linked Viagra and other anti-impotence drugs to side effects such as deafness.

American researchers also found that men who used Viagra increased their risk of developing skin cancer. 

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Retinitis pigmentosa is a rare hereditary condition that causes the cells in the retina - the area of the back of the eye which detects light - to degenerate and die

Read more: http://www.dailymail.co.uk/health/article-2776190/Viagra-cause-blindness-Ingredient-drug-permanently-affect-sight-doctors-warn.html#ixzz3EulJKRIc 
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Why a spoon WON'T help the medicine go down: Risk of dosage mistakes is 50% higher, doctors warn

Almost one-third of the parents give the wrong dose, a study found 

Incorrect doses included giving too much and too little - both are dangerous 

Droppers and syringes that measure in milliliters should be used instead

Using a spoon to measure medicine for children can lead to potentially dangerous dosing mistakes, a study claims.

Instead, parents are encouraged to use droppers and syringes which measure in millilitres when giving liquid medicines.

In the most recent test parents who used spoonfuls ‘were 50 per cent more likely to give their children incorrect doses than those who measured in more precise millilitre units’.

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More harm than good? Parents who used spoonfuls 'were 50 per cent more likely to give their children incorrect doses, a study found

Incorrect doses included giving too much and too little, which can both be dangerous said Dr Alan Mendelsohn, the report’s co-author and associate professor at New York University’s medical school. He explained underdosing may not adequately treat an illness and can lead to medication-resistant infections, while overdoses may cause illness or side effects that can be life-threatening.

 

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The study, published in the journal Pediatrics, involved nearly 300 parents with children under nine.

They were treated for various illnesses at two New York City emergency rooms and sent home with prescriptions for liquid medicines, mostly antibiotics.

Parents were contacted afterwards by telephone and asked how they had measured the prescribed doses.

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Safer: Droppers and syringes that measure in milliliters should be used for liquid medicines, say doctors

They also brought their measuring devices to the researchers’ offices to demonstrate doses they’d given their children.

Almost a third of the parents involved gave the wrong dose and one in six used a kitchen spoon rather than a device such as an oral syringe or dropper, that lists doses in millilitres. Less than half the prescriptions specified doses in millilitres. But even when they did, the medicine bottle label often listed doses in teaspoons.

Parents often assume that means any similar-sized kitchen spoon, the report said, and they fail to use a precise teaspoon measure. The study found 43 per cent of parents who measured out the medicine using some sort of spoon had made a mistake, compared to only 28 per cent of those measuring the medication in precise millilitres.

And 45 percent of parents using teaspoon or tablespoon measurements made an error despite knowing what the correctly prescribed dose was supposed to be, compared to 31 percent of parents using millilitres to measure medication.

Dr Mendelsohn suggested pharmacists and other health professionals should be enlisted to promote the consistent use of millilitre units on prescriptions and labels on  medicine bottles.

Read more: http://www.dailymail.co.uk/health/article-2690759/Spoonfuls-lead-medicine-errors-study-finds.html#ixzz37UlRRxeI 
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