Impotence drugs could damage eyes

Impotence drugs such as Viagra and Cialis can increase the risk of eye damage in men who have a history of heart disease or high blood pressure. Researchers from the University of Alabama in Birmingham found that men who had suffered a heart attack were 10 times more likely to have optic nerve damage if they had been taking anti-impotence pills containing sildenafil or tadalafil. In patients with a history of myocardial infarction (heart attack), a strong link between the use of Viagra and/or Cialis and an increased risk of non-arteritic anterior ischaemic optic neuropathy (NAION) was observed. NAION is the most common cause of acute optic nerve disease in people over 50 years old. It can cause permanent loss of vision in one or both eyes. Penegra, made by Zydus Cadila and Zydalis, made by Cadila Pharmaceuticals Ltd. are used commonly for treating impotence. The researching team questioned 76 men, half of whom suffered from NAION, who were treated at a specialist eye clinic in the United States, about their smoking and drinking habits and use of anti-impotence pills. The researchers found that men who had had a heart attack were 10 times more likely to have optic nerve damage if they had taken the anti-impotence drugs. Tens of millions of men had used Viagra and Cialis since the tablets were launched. The Food and Drug Administration (FDA) in the United States said it had received more than 40 reports of NAION involving impotence drugs but had not determined whether the treatments were responsible. Pfizer said a review of 103 Viagra clinical trials involving more than 13,000 patients found no reports of NAION. But the company has changed the label on Viagra to note reports of NAION. Eli Lilly has also changed its labels on Cialis. Patients with heart disease or high blood pressure should be warned about the elevated risk of NAION when taking anti-impotence pills. Though NAION is a rare condition, but men using Viagra or Cialis suggest that, if an association truly exists, the incidence of NAION could rise dramatically.