MINNEAPOLIS, MAY 28, 2005: The Food and Drug Administration is probing whether impotence drugs such as Viagra and Cialis are linked to blindness and partial vision loss in some men, the agency announced on Friday.
The FDA said it has 43 reports of such problems, including seven from a University of Minnesota ophthalmologist. The federal agency cautioned there is no evidence that the drugs cause the problem and that the reports of it are exceedingly rare. About 30 million men around the world have used the drugs since Viagra was first introduced in 1998.
But Dr Howard Pomeranz, the university researcher and associate professor, said he thinks the drugs are suspect because vision loss in six patients occurred within 24 hours of taking the drug. And it might happen more often than anyone knows, he said. Men who suffer the vision problem, which results from blood loss to the optic nerve, may not volunteer they are taking drugs for impotence, he said.
‘‘I think the investigation is worthwhile,’’ Pomeranz said. And anyone taking the drugs ‘‘owe themselves a visit to their eye doctor for possible risk’’, he said.
The disclosure comes at a time when the drug industry is already reeling from reports of harm from other blockbuster drugs, including Vioxx and Celebrex, and the FDA has been criticised for not acting fast enough to make new risks public.
Viagra is one of the biggest selling drugs made by Pfizer Inc., with nearly $1 billion in sales last year. In all, the three largest selling impotence drugs generated more than $1.3 billion in sales last year, according to the drug tracking firm IMS Health.
Pfizer said in a statement on Friday that it is discussing with FDA about adding a warning to Viagra’s label. Cialis, made by Eli Lilly & Co. and ICOS Corp., has already done so voluntarily.
FDA spokesperson Susan Cruzan said 38 of the eye-problem cases are related to Viagra, four cases are linked Cialis, the second largest selling drug, and one case was linked to Levitra.
Labels on all three drugs already warn about possible eyesight problems, including blurred vision, and trouble distinguishing blue from green. This eye problem is different. Pomeranz said the loss of vision, which can be complete, occurs due to a ‘‘stroke of the eye’’. The FDA said this usually occurs in older men. – NYT