A recent scientific journal reported a possible link between Viagra and instances of blindness, yet the Food and Drug Administration was aware of the connection over a year earlier and did not make the information public until after the study was published. The agency has been criticized for its slow response to information about the harmful side effects, especially after Merck pulled Vioxx from the market last year due to the risk of heart attack and stroke.
Read more: FDA Was Told of Viagra-Blindness Link Months Ago.
Washington Post staff writer Marc Kaufman was online Friday, July 1, at Noon ET to discuss the FDA's handling of information on the possible link between Viagra and blindness.
A transcript follows.
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Marc Kaufman: Good morning, and thanks for joining this chat. The subject is Viagra and a rare form of blindness called NAOIN, or non-arthritic anterior ischemic optic neuropathy. Some academic researchers published information about a possible link several months ago, and then the news of that possible association became quite a news story. The story I wrote in today's Post adds this information: More than a year ago, a safety officer at the FDA noticed the same association, wrote up a report for her supervisors, apparently convinced them that there was a potential problem, and then nothing happened. Critics of the agency, such as Sen. Charles Grassley, accuse the agency of foot-dragging on this issue, and on many other safety concerns regarding drugs on the market. The agency chose not to comment on Grassley's letter, but they often say they're in the business of weighing the risks of drugs and the benefits--and that is a difficult and sometimes time-consuming process.
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Rockville, Md.: Any relationship established between blindness and the other ED drugs?
Marc Kaufman: The FDA is examining some similar reports regarding Cialis and Levitra, and the makers of Pfizer have said the agency intends to ask all manufacturers of ED drugs to add information to their labels describing the possible link. All three already have warnings that the drugs can cause a variety of relatively minor eye problems, and Cialis has voluntarily added some information about the research regarding sudden blindness.
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Concord, N.C.: Greetings: Does frequency of taking Viagra increase the risk? Is there a threshold of use that has been detected that increases the risk? Thanks.
Marc Kaufman: No, there has not been any indication that frequency of use, or dose, necessarily matters. But truth be told, research into the possible link is just beginning and we don't really have a good idea of how frequent the sudden blindness response may be. We do know, however, that some people who use ED drugs because of medical conditions they have may well be at risk of NAOIN because of their ailment, as well as possibly the drugs.
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Concord, N.C.: Is there any way to know if you are predisposed to be susceptible to the blindness problem? Any present side effects that are occurring being a precursor to being susceptible to blindness problem? Does border line glaucoma increase the risk when taking Viagra? What tests, if any, can be taken to check the possibility and potential of risk? Thanks.
Marc Kaufman: The medical record shows that people at risk of NAOIN are those over 50, with high cholesterol or diabetes, and who smoke. That is a pretty large population, and includes many of those who take VIAGRA and other ED drugs. I believe that when the FDA and companies agree on some labeling for the new information, they will probably indicate who might be most at risk. It's important to emphasize that the link is quite rare, and that Pfizer, the FDA and the academic researchers who have begun looking at the issue all say there is no cause-and-effect relationship established at this time. But with more research, that could change.
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Marc Kaufman: Thanks for your questions. I suspect there will be more news in the future on these two subjects -- Viagra/sudden blindness and general FDA safety issues -- so stay tuned.
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