title: Long-term treatment of erectile dysfunction with a phosphodiesterase-5 inhibitor and dose optimization based on nocturnal penile tumescence.
abstract: OBJECTIVE
  To test the hypothesis that a variable dosage of the oral phosphodiesterase type 5 (PDE5) inhibitor sildenafil (25, 50, 100 mg) or vardenafil (5, 10, 25 mg) determined according to results obtained from nocturnal penile tumescence and rigidity (NPTR, RigiScan), given nightly for 1 year, can improve spontaneous erectile function (EF) in men with mild-to-moderate arteriogenic erectile dysfunction (ED); this regimen was compared with a fixed daily dosage of sildenafil 25 mg or vardenafil 5 mg.
  
  
  METHODS
  In a prospective open-label, parallel-group trial 154 men with ED were randomized either to fixed low-dose sildenafil 25 mg or vardenafil 5 mg (group 1) or to the lowest erectile dosage of sildenafil (25, 50 or 100 mg) or vardenafil (5, 10 or 20 mg) (group 2) provoking an erectile event as measured by NPTR nightly for 1 year. The EF domain of the International Index of Erectile Function (IIEF) was assessed before and 1 year after the beginning of treatment, and at 4 weeks after ending treatment.
  
  
  RESULTS
  After 1 year, 27 of 63 (64%) evaluable men in group 1 had an EF domain score in the normal range, vs 46 of 61 (75%) men in group 2. After the subsequent 4-week wash-out phase, both groups continued to have improved EF domain scores; 22 of 63 (35%) men in group 1 still had a score in the normal range, whereas 38 of 61 (62%) in group 2 had a normal score. The EF domain score in group 1 and 2 improved significantly after 1 year of treatment, from 13.6 to 18.9, and 15.1 to 23.9, respectively (P < 0.01). After the subsequent 4-week wash-out phase, men from both groups maintained this significant level of EF, at 17.1 and 22.4, respectively (P < 0.05).
  
  
  CONCLUSIONS
  Nightly PDE5-inhibitor treatment 1 year in a dosage determined by NPTR measurements results in better EF than giving a fixed dosage of sildenafil (25 mg) or vardenafil (5 mg). This improvement persisted for >4 weeks beyond the end of treatment. The results from this open-label, randomized trial warrant verification under double-blind, placebo-controlled conditions.
authors.affiliation: Urological Ambulatory Remscheid, Remscheid, Germany. irtima@t-online.de
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Mathers
authors.forename: Theodor
authors.initials: T
authors.lastname: Klotz
authors.forename: Alexander S
authors.initials: AS
authors.lastname: Brandt
authors.forename: Stephan
authors.initials: S
authors.lastname: Roth
authors.forename: Frank
authors.initials: F
authors.lastname: Sommer
mesh_terms: D000328:Adult; D000368:Aged; D006801:Humans; D007093:Imidazoles / Q000008:administration & dosage* / Q000009:adverse effects; D018783:Impotence, Vasculogenic / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D010410:Penile Erection / Q000187:drug effects*; D010726:Phosphodiesterase Inhibitors / Q000008:administration & dosage* / Q000009:adverse effects; D010879:Piperazines / Q000008:administration & dosage* / Q000009:adverse effects; D011446:Prospective Studies; D011687:Purines / Q000008:administration & dosage / Q000009:adverse effects; D000068677:Sildenafil Citrate; D013450:Sulfones / Q000008:administration & dosage* / Q000009:adverse effects; D013997:Time Factors; D016896:Treatment Outcome; D014227:Triazines / Q000008:administration & dosage / Q000009:adverse effects; D000069058:Vardenafil Dihydrochloride
chemical_list: D007093:Imidazoles; D010726:Phosphodiesterase Inhibitors; D010879:Piperazines; D011687:Purines; D013450:Sulfones; D014227:Triazines; D000069058:Vardenafil Dihydrochloride; D000068677:Sildenafil Citrate