Nonarteritic ischaemic optic neuropathy (NAION) after 36 h of intake of sildenafil citrate: first Egyptian case.

Sildenafil citrate is a selective phosphodiesterase 5 (PDE-5) inhibitor and partial phosphodiesterase 6 inhibitor prescribed for erectile dysfunction. Post-marketing case reports of nonarteritic anterior ischaemic optic neuropathy (NAION) over the past few years suggest a potential link with PDE-5 inhibitors. We report a case of a 48-year-old male patient who had acute vision loss 36 h after the intake of 50 mg sildenafil citrate. NAION occurred at a period of minimal blood level of sildenafil citrate. So, erectile dysfunction drugs must be strongly considered with NAION even though their users may have neither predisposing nor precipitating factors for NAION and even if occurring at a time of minimal blood level of these drugs.