Sildenafil can induce the onset of a cluster headache bout.

About 25% of patients who are prescribed sildenafil, the phosphodiesterase type 5 (PDE-5) inhibitor, for erectile dysfunction (ED) experience headaches. These migraine effects are well-described, including cluster headaches. We report the case of a man who experienced a cluster headache attack following each of 2 sildenafil doses. His symptoms were resolved by adding naproxen to his treatment regimen and changing his ED treatment from 50 mg of sildenafil to 5 mg of vardenafil. To our knowledge, no study has reported cluster headaches triggered by the less commonly used PDE-5 inhibitors, namely vardenafil and tadalafil. Urologists should be cautious in prescribing sildenafil to patients with ED and with a history of cluster headaches. In these patients, they should consider prescribing low-dose vardenafil or tadalafil instead. Failure to recognize sildenafil risks could result in unnecessary headache bouts in patients with a history of cluster headaches.