LAUSR

Abstract The phosphodiesterase (PDE)-5 inhibitor sildenafil is a commonly used drug to treat erectile dysfunction. As its vascular relaxation effects might affect not only the corpus cavernosum, but as well vasculature in general, an association with bleeding incidents has been discussed. We report on a 55-year-old patient presenting with thunderclap headache due to perimesencephalic subarachnoid hemorrhage (SAH) after ingestion of a very high dose (200 mg) of sildenafil. No aneurysm or other vascular abnormality was found as a cause of the bleeding. We discuss possible mechanisms by which sildenafil might alter intracranial blood coagulation, e.g. via acting on the PDE-1 and PDE-2 enzymes and via affecting platelet aggregation. In conclusion, Sildenafil may cause or intensify extra- and intracranial hemorrhage. Thus, careful discussion and indication are mandatory. On the other hand, sildenafil is also addressed as a potential option in the prevention and treatment for cerebral vasospasm as complication of SAH.