The United States Food and Drug Administration (FDA) issued a consumer alert on July 8, 2005, regarding the erectile dysfunction drugs Viagra, Cialis and Levitra.

The FDA is investigating reports from men who have lost their eyesight, usually in one eye, after taking these drugs. The vision loss is a result of a condition called non-arteritic anterior ischemic optic neuropathy, or NAION, which causes a sudden loss of eyesight due to blocking blood flow to the optic nerve. NAION is an irreversible condition.

The FDA cautions that it does not yet know if Viagra, Cialis or Levitra causes NAION, but warns that men have a higher chance of NAION when taking Viagra, Cialis, or Levitra if they:

• Have heart disease
• Are over 50 years of age
• Have diabetes
• Have high blood pressure
• Have high cholesterol
• Smoke
• Have eye problems

The FDA has approved new labels for Viagra, Cialis and Levitra to include warnings on possible eyesight loss from NAION. Patients who experience a loss in eyesight should stop using erectile dysfunction drugs.