title: Evaluation of the effects of sildenafil citrate (viagra) on vertebral artery blood flow in patients with vertebro-basilar insufficiency.
abstract: OBJECTIVE
  To investigate the effects of sildenafil citrate (Viagra) on the vertebral artery blood flow of patients with vertebro-basilar insufficiency (VBI) using color duplex sonography (CDS).
  
  
  METHODS
  The study included 21 patients with VBI (aged 31-76; mean 61.0 +/- 10.5 yrs). We administered a 50 mg oral dose of sildenafil citrate to all patients. Next, we measured the peak systolic velocity (Vmax), end diastolic velocity (Vmin), resistive index (RI), pulsatility index (PI), diameter, area, and flow volume (FV) of vertebral arteries using CDS before the administration of sildenafil citrate; 45 minutes after, and 75 minutes after administration. Statistical testing was performed using SPSS for windows version 11.0. The statistical test used to determine the outcome of the analysis was the repeated measures analysis of variance (ANOVA) test.
  
  
  RESULTS
  Compared to the baseline values, the vertebral artery diameter, area, and FV increased significantly following the administration of sildenafil citrate. The diameter, area and FV increased from 3.39 mm at 45 minutes to 3.64 mm at 75 minutes, 9.43 cm(2) to 10.80 cm(2) at 45 minutes and 10.81 cm(2) at 75 minutes, as well as from 0.07 L/min at baseline to 0.09 L/min at 45 minutes and unchanged at 75 minutes, respectively.
  
  
  CONCLUSIONS
  Sildenafil citrate elicited a significant effect on vertebral artery diameter, area and FVs.
authors.affiliation: Firat University School of Medicine, Department of Radiology, Elazig, Turkey. bozgeyik4@hotmail.com
authors.forename: Zulkif
authors.initials: Z
authors.lastname: Bozgeyik
authors.forename: Sait
authors.initials: S
authors.lastname: Berilgen
authors.forename: Huseyin
authors.initials: H
authors.lastname: Ozdemir
authors.forename: Aslan
authors.initials: A
authors.lastname: Tekatas
authors.forename: Erkin
authors.initials: E
authors.lastname: Ogur
mesh_terms: D000328:Adult; D000368:Aged; D001783:Blood Flow Velocity / Q000187:drug effects; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010879:Piperazines / Q000494:pharmacology*; D011673:Pulsatile Flow / Q000187:drug effects; D011687:Purines / Q000494:pharmacology; D000068677:Sildenafil Citrate; D013450:Sulfones / Q000494:pharmacology*; D018615:Ultrasonography, Doppler, Color; D014655:Vascular Resistance / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology*; D014711:Vertebral Artery / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000503:physiopathology; D014715:Vertebrobasilar Insufficiency / Q000000981:diagnostic imaging / Q000503:physiopathology*
chemical_list: D010879:Piperazines; D011687:Purines; D013450:Sulfones; D014665:Vasodilator Agents; D000068677:Sildenafil Citrate