title: Long-term oral phosphodiesterase 5 inhibitor therapy alleviates recurrent priapism.
abstract: OBJECTIVE
  Recurrent ischemic priapism describes a disorder of repeated episodes of prolonged penile erection that frequently leads to devastating complications of erectile tissue damage and erectile dysfunction. A mechanistic role for dysregulated phosphodiesterase 5 (PDE5) in the deranged smooth muscle response of the corpus cavernosum of the penis offers new understanding about the pathogenesis of the disorder and suggests that PDE5 may serve as a molecular target for its treatment and prevention. We explored the use of PDE5 inhibitors to treat recurrent priapism, based on the hypothesis that the erection regulatory function of PDE5 would be regularized by this treatment and protect against further episodes.
  
  
  METHODS
  We administered PDE5 inhibitors using a long-term therapeutic regimen to 3 men with sickle cell disease-associated priapism recurrences and 1 man with idiopathic priapism recurrences.
  
  
  RESULTS
  Long-term PDE5 inhibitor treatment alleviated priapism recurrences.
  
  
  CONCLUSIONS
  These observations support the hypothesis that PDE5 dysregulation exerts a pathogenic role for priapism associated with hematologic dyscrasias, as well as idiopathic priapism. Although these preliminary findings suggest that continuous, long-term PDE5 inhibitor therapy may be useful as a preventative strategy for priapism, additional evaluation in the form of a controlled clinical trial is needed.
authors.affiliation: Department of Urology, James Buchanan Brady Urological Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA. aburnett@jhmi.edu
authors.forename: Arthur L
authors.initials: AL
authors.lastname: Burnett
authors.forename: Trinity J
authors.initials: TJ
authors.lastname: Bivalacqua
authors.forename: Hunter C
authors.initials: HC
authors.lastname: Champion
authors.forename: Biljana
authors.initials: B
authors.lastname: Musicki
mesh_terms: D015106:3',5'-Cyclic-GMP Phosphodiesterases; D000328:Adult; D000755:Anemia, Sickle Cell / Q000150:complications; D002243:Carbolines / Q000627:therapeutic use*; D054706:Cyclic Nucleotide Phosphodiesterases, Type 5; D007172:Erectile Dysfunction / Q000209:etiology; D006801:Humans; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism; D010410:Penile Erection / Q000187:drug effects / Q000502:physiology; D010726:Phosphodiesterase Inhibitors / Q000627:therapeutic use*; D010727:Phosphoric Diester Hydrolases; D010879:Piperazines / Q000627:therapeutic use*; D011317:Priapism / Q000188:drug therapy* / Q000209:etiology / Q000378:metabolism / Q000628:therapy; D011687:Purines; D012008:Recurrence; D015398:Signal Transduction; D000068677:Sildenafil Citrate; D013450:Sulfones; D000068581:Tadalafil
chemical_list: D002243:Carbolines; D010726:Phosphodiesterase Inhibitors; D010879:Piperazines; D011687:Purines; D013450:Sulfones; D009569:Nitric Oxide; D000068581:Tadalafil; D000068677:Sildenafil Citrate; D010727:Phosphoric Diester Hydrolases; D015106:3',5'-Cyclic-GMP Phosphodiesterases; D054706:Cyclic Nucleotide Phosphodiesterases, Type 5; C517381:PDE5A protein, human