title: Endothelial antioxidant administration ameliorates the erectile response to PDE5 regardless of the extension of the atherosclerotic process.
abstract: BACKGROUND
  The lack of phosphodiesterase type 5 inhibitor effects in patients with erectile dysfunction (ED) of arterial origin may be caused by an endothelial dysfunction that causes a series of biochemical alterations leading to a reduced nitric oxide (NO) bioavailability and increased oxidative stress.
  
  
  OBJECTIVE
  The aim of this study was to evaluate the effects of the treatment with endothelial antioxidant compounds (EAC) on the erectile response to sildenafil in patients with arterial ED already treated with sildenafil (100 mg twice a week for 8 weeks).
  
  
  METHODS
  A patient was considered responsive when the 5-item International Index of Erectile Function questionnaire score increased by >5 points.
  
  
  METHODS
  Fifty-three patients with arterial ED, hypertension, and diabetes mellitus were randomly given, for 8 weeks, EAC (1 dose/day) and, after a wash out of 8 weeks, sildenafil (100 mg) plus EAC. The patients were divided into the following four groups: A (N = 12): patients with ED alone; B (N = 14): patients with ED plus atheromasic plaques and/or increased intima-media thickness of common carotid arteries; C (N = 14): patients with ED plus lower limb artery abnormalities; and D (N = 13): patients with ED plus carotid and lower limb artery abnormalities.
  
  
  RESULTS
  The administration of EAC plus sildenafil resulted in a significantly higher number of responsive patients (N = 36, 68%) compared with sildenafil alone (N = 24, 45%) or EAC alone (N = 17, 32%). The percentage of patients who successfully responded to the combined treatment increased in the various groups. It was 83%, 64%, 71%, and 54%, respectively, for groups A, B, C, and D. Furthermore, patients treated with EAC and sildenafil reached a successful response in a shorter length of time (3 weeks) compared with patients responsive to sildenafil (5.2 weeks) or EAC (5.7 weeks) alone.
  
  
  CONCLUSIONS
  EAC administration to patients with arterial ED improved the success rate to sildenafil. These data suggest that, in such patients, a combined treatment may be considered to increase bioavailable NO and to neutralize radical oxygen species, which in turn inactive NO.
authors.affiliation: Section of Endocrinology, Andrology and Internal Medicine, and Master in Andrological and Human Reproduction Sciences, Department of Biomedical Sciences, University of Catania, Catania, Italy. enzodante@email.it
authors.forename: Enzo
authors.initials: E
authors.lastname: Vicari
authors.forename: Sandro
authors.initials: S
authors.lastname: La Vignera
authors.forename: Rosita
authors.initials: R
authors.lastname: Condorelli
authors.forename: Aldo Eugenio
authors.initials: AE
authors.lastname: Calogero
mesh_terms: D000368:Aged; D001682:Biological Availability; D003324:Coronary Artery Disease / Q000150:complications* / Q000503:physiopathology*; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000378:metabolism* / Q000503:physiopathology; D007172:Erectile Dysfunction / Q000175:diagnosis / Q000188:drug therapy* / Q000453:epidemiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000378:metabolism; D018384:Oxidative Stress / Q000502:physiology; D058986:Phosphodiesterase 5 Inhibitors; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology / Q000627:therapeutic use*; D010879:Piperazines / Q000494:pharmacology / Q000627:therapeutic use*; D011687:Purines / Q000494:pharmacology / Q000627:therapeutic use; D012720:Severity of Illness Index; D000068677:Sildenafil Citrate; D013450:Sulfones / Q000494:pharmacology / Q000627:therapeutic use*; D011795:Surveys and Questionnaires
chemical_list: D058986:Phosphodiesterase 5 Inhibitors; D010726:Phosphodiesterase Inhibitors; D010879:Piperazines; D011687:Purines; D013450:Sulfones; D009569:Nitric Oxide; D000068677:Sildenafil Citrate