title: The effect of sildenafil citrate (Viagra) on cerebral blood flow in patients with cerebrovascular risk factors.
abstract: OBJECTIVE
  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.
  
  
  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.
authors.affiliation: Department of Nuclear Medicine, Edith Wolfson Medical Center, Holon, Israel. mvlorber@zahav.net.il <mvlorber@zahav.net.il>
authors.forename: M
authors.initials: M
authors.lastname: Lorberboym
authors.forename: I
authors.initials: I
authors.lastname: Mena
authors.forename: J
authors.initials: J
authors.lastname: Wainstein
authors.forename: M
authors.initials: M
authors.lastname: Boaz
authors.forename: Y
authors.initials: Y
authors.lastname: Lampl
mesh_terms: D000328:Adult; D000368:Aged; D001931:Brain Mapping; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D002561:Cerebrovascular Disorders / Q000150:complications* / Q000000981:diagnostic imaging; D007172:Erectile Dysfunction / Q000188:drug therapy / Q000209:etiology / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology* / Q000627:therapeutic use; D010879:Piperazines / Q000494:pharmacology* / Q000627:therapeutic use; D011687:Purines / Q000494:pharmacology / Q000627:therapeutic use; D019275:Radiopharmaceuticals; D012307:Risk Factors; D000068677:Sildenafil Citrate; D013450:Sulfones / Q000494:pharmacology* / Q000627:therapeutic use; D019690:Technetium Tc 99m Exametazime; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods
chemical_list: D010726:Phosphodiesterase Inhibitors; D010879:Piperazines; D011687:Purines; D019275:Radiopharmaceuticals; D013450:Sulfones; D019690:Technetium Tc 99m Exametazime; D000068677:Sildenafil Citrate