The effect of sildenafil citrate (Viagra) on cerebral blood flow in patients with cerebrovascular risk factors.
OBJECTIVES
Sildenafil citrate is widely used for erectile dysfunction. The present study examined the short-term effects of sildenafil administration in individuals with cerebrovascular risk factors, including patients with a history of stroke.


MATERIALS AND METHODS
Twenty-five consecutive male patients with erectile dysfunction and vascular risk factors were included in the study. A perfusion brain SPECT study was performed at baseline and 1 h after the oral administration of sildenafil.


RESULTS
Associations between any of the risk factors and the perfusion scores were not detected, with the exception of stroke. Stroke patients showed significantly more areas with diminished perfusion after sildenafil administration compared to baseline.


CONCLUSIONS
In patients with diabetes or hypertension, a dose of 50 mg sildenafil does not appear to produce detrimental effects on cerebral blood flow. However, patients with a history of stroke may be at increased risk of hemodynamic impairment after the use of sildenafil.