title: Effects of sildenafil citrate (Viagra) on renal arteries: an evaluation with Doppler ultrasound.
abstract: BACKGROUND
  We aimed to determine hemodynamic alterations in renal arteries that may have resulted from oral intake of sildenafil citrate in healthy volunteers.
  
  
  METHODS
  Twelve healthy volunteers were included in our study. Renal Doppler ultrasonography (US) was performed before the drug intake to assess the basal values. Maximum peak systolic velocity, and resistivity and pulsatility indices were measured from the segmental branches of both renal arteries in all the examinations. After the basal measurements 50 mg of sildenafil or placebo were randomly given to the 12 subjects. Renal Doppler US examinations were carried out 1 h after sildenafil or placebo intake. On the following day sildenafil was administered to the subjects who had previously taken placebo or vice versa. Renal Doppler US was repeated after 1 h. The effect of sildenafil on renal vascular hemodynamics was evaluated by comparison of basal values with postplacebo and postsildenafil values.
  
  
  RESULTS
  No statistically significant differences were found between the basal values of bilateral renal arteries and maximum peak systolic velocity, and resistivity and pulsatility index values measured after the placebo or sildenafil intake.
  
  
  CONCLUSIONS
  We demonstrated that single-dose sildenafil did not cause any significant effect on renal artery hemodynamics in healthy individuals.
authors.affiliation: Department of Radiology, Afyon Kocatepe University Faculty of Medicine, Afyonkarahisar, Turkey. bumin.degirmenci@gmail.com
authors.forename: Bumin
authors.initials: B
authors.lastname: Degirmenci
authors.forename: Murat
authors.initials: M
authors.lastname: Acar
authors.forename: Ramazan
authors.initials: R
authors.lastname: Albayrak
authors.forename: Alpay
authors.initials: A
authors.lastname: Haktanir
authors.forename: Aylin
authors.initials: A
authors.lastname: Yucel
authors.forename: Omer
authors.initials: O
authors.lastname: Gecici
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity; D006801:Humans; D008297:Male; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology*; D010879:Piperazines / Q000494:pharmacology*; D011687:Purines; D012077:Renal Artery / Q000000981:diagnostic imaging* / Q000187:drug effects* / Q000502:physiology; D000068677:Sildenafil Citrate; D013450:Sulfones; D018615:Ultrasonography, Doppler, Color; D014655:Vascular Resistance
chemical_list: D010726:Phosphodiesterase Inhibitors; D010879:Piperazines; D011687:Purines; D013450:Sulfones; D000068677:Sildenafil Citrate