title: Randomized controlled trial of sildenafil for preventing recurrent ischemic priapism in sickle cell disease.
abstract: BACKGROUND
  Successful preventive therapy for ischemic priapism, a disorder of penile erection with major physical and psychologic consequences, is limited. We conducted a randomized, double-blind, placebo-controlled clinical trial to assess the efficacy and safety of sildenafil by a systematic dosing protocol to prevent recurrent ischemic priapism associated with sickle cell disease.
  
  
  METHODS
  Thirteen patients with sickle cell disease reporting priapism recurrences at least twice weekly were randomized to receive sildenafil 50 mg or placebo daily, unassociated with sleep or sexual activity, for 8 weeks, followed by open-label use of this sildenafil regimen for an additional 8 weeks.
  
  
  RESULTS
  Priapism frequency reduction by 50% did not differ between sildenafil and placebo groups by intention-to-treat or per protocol analyses (P = 1.0). However, during open-label assessment, 5 of 8 patients (62.5%) by intention-to-treat analysis and 2 of 3 patients (66.7%) by per protocol analysis met this primary efficacy outcome. No significant differences were found between study groups in rates of adverse effects, although major priapism episodes were decreased 4-fold in patients monitored "on-treatment."
  
  
  CONCLUSIONS
  Sildenafil use by systematic dosing may offer a strategy to prevent recurrent ischemic priapism in patients with sickle cell disease.
authors.affiliation: The James Buchanan Brady Urological Institute and Department of Urology, The Johns Hopkins School of Medicine, Baltimore, Md. Electronic address: aburnet1@jhmi.edu.
authors.forename: Arthur L
authors.initials: AL
authors.lastname: Burnett
authors.affiliation: The James Buchanan Brady Urological Institute and Department of Urology, The Johns Hopkins School of Medicine, Baltimore, Md.
authors.forename: Uzoma A
authors.initials: UA
authors.lastname: Anele
authors.affiliation: The James Buchanan Brady Urological Institute and Department of Urology, The Johns Hopkins School of Medicine, Baltimore, Md.
authors.forename: Irene N
authors.initials: IN
authors.lastname: Trueheart
authors.affiliation: Division of Pediatric Hematology, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Md.
authors.forename: John J
authors.initials: JJ
authors.lastname: Strouse
authors.affiliation: Division of Pediatric Hematology, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Md.
authors.forename: James F
authors.initials: JF
authors.lastname: Casella
mesh_terms: D000293:Adolescent; D000328:Adult; D000755:Anemia, Sickle Cell / Q000150:complications*; D004311:Double-Blind Method; D006801:Humans; D007511:Ischemia / Q000150:complications* / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D058986:Phosphodiesterase 5 Inhibitors / Q000627:therapeutic use*; D010879:Piperazines / Q000627:therapeutic use*; D011317:Priapism / Q000209:etiology* / Q000517:prevention & control*; D011446:Prospective Studies; D011687:Purines / Q000627:therapeutic use; D012008:Recurrence; D000068677:Sildenafil Citrate; D013450:Sulfones / Q000627:therapeutic use*; D055815:Young Adult
chemical_list: D058986:Phosphodiesterase 5 Inhibitors; D010879:Piperazines; D011687:Purines; D013450:Sulfones; D000068677:Sildenafil Citrate
keywords: Erectile dysfunction; Erection; Nitric oxide; Phosphodiesterase type 5