In the Press

(CBS) Pfizer Statement Regarding Viagra

Many news reports described the potential risk of drugs like Viagra and blindness. In fact, the reports concerning visual changes and use of the class of drugs called PDE5 inhibitors have circulated since the approval of Viagra in 1998.

Although from a clinical perspective Viagra and less frequently Levitra and Cialis can all cause temporary visual changes, these rarely have important clinical implications. The reports about blindness however were describing a condition related to reduced blood flow to the optic nerve, a condition which represents the most common cause of blindness among men over 50 years of age.

Over the past few years more than 40 million men have used this class of drug and to date based on a number of studies in the USA and Europe, there exists no evidence to show any additional risk of developing what is called NAION (nonarterial ischemic optic neuropathy) when a PDE5i is used. Physicians and regulatory bodies are always very careful however and the final reports will require many more detailed studies to say conclusively that no additional risk exists. Until that time, based on the existing information I let my patients know that the real chance of any of them ever developing this type of visual problem as a consequence of using a PDE5i is very rare.

Gerald Brock MD, FRCSC