Visual loss with erectile dysfunction medications

Reason for posting: Phosphodiesterase type 5 (PDE5) inhibitors, including sildenafil (Viagra), tadalafil (Cialis) and vardenafil (Levitra), are drugs used to treat erectile dysfunction that have long been recognized to cause temporary, minor visual changes in less than 10% of users.1 However concerns were raised in 2005 after a small case series was published describing several sildenafil users who experienced sudden, severe visual loss. Health Canada recently issued a warning that the condition known as nonarteritic ischemic optic neuropathy (NAION; see Box 1) has been reported in users of all the PDE5 inhibitors.2 What to do: Patients should be warned of this very rare but potentially serious and often irreversible adverse effect. Patients with many vascular risk actors (who may also be more likely to have erectile dysfunction) may be at greatest risk. It is not yet clear whether the background population rate of NAION is lower than that seen among PDE5 inhibitor users. The drugs should not be prescribed to people with previous NAION. If symptoms of NAION occur, use of the drug should be stopped and urgent ophthalmologic attention sought. Patients presenting with NAION should be questioned about any history of PDEs inhibitor use.