title: Does sildenafil enhance quality of nocturnal erections in healthy young men? A NPT-RigiScan study.
abstract: OBJECTIVE
  To assess the effect of sildenafil on nocturnal erectile function (EF) in young healthy volunteers with normal sexual function (SF) according to the International Index of Erectile Function (IIEF) questionnaire.
  
  
  METHODS
  Thirty-three young (mean age 21 +/- 0.3 years; range 18-25) healthy volunteers not taking any medications who had normal SF and an EF domain >26 on the IIEF questionnaire were evaluated. Erectile function was assessed using the RigiScan (Dacomed Corp., MN, USA) during three nights: night 1 = adaptation to the NPT-Rigiscan apparatus, night 2 = baseline recording of eight parameters, and night 3 = recordings after ingestion of sildenafil 100 mg. Data on the number of erections, erection duration, minimal and maximal base tumescence, minimal and maximal tip tumescence, and base and tip rigidity were analysed using anova with repeated measures.
  
  
  RESULTS
  A statistically significant improvement in all eight parameters was observed as a result of sildenafil administration: number of erections from 3.1 +/- 0.7 to 4.0 +/- 0.7 (P < 0.05), erection time 22 +/- 3.5 to 34.2 +/- 5.9, minimal base tumescence 8.2 +/- 0.8 to 8.7 +/- 0.8, maximal base tumescence 12.1 +/- 0.7 to 14.2 +/- 0.7, base rigidity 75.6 +/- 3.1 to 81.6 +/- 3.6, tip rigidity 70.6 +/- 1.5 to 75.9 +/- 3.1, minimal tip tumescence 5.9 +/- 0.5 to 6.5 +/- 0.6, and maximal tip tumescence 8.6 +/- 0.6 to 11.7 +/- 0.7 (P < 0.0001 for each of the last seven parameters). The mean sleep duration, 7.3 hours (range 6.30-9.20 hours), was similar for both nights of recording.
  
  
  CONCLUSIONS
  Sildenafil increases the quality and number of nocturnal erections as tested by the NPT-RigiScan in young healthy volunteers with normal EF.
authors.affiliation: Department of Urology, Tel Aviv Sourasky Medical Centre, Tel Aviv, Israel. surge04@post.tau.ac.il
authors.forename: Alexander
authors.initials: A
authors.lastname: Greenstein
authors.forename: Juza
authors.initials: J
authors.lastname: Chen
authors.forename: Andrea
authors.initials: A
authors.lastname: Salonia
authors.forename: Mario
authors.initials: M
authors.lastname: Sofer
authors.forename: Haim
authors.initials: H
authors.lastname: Matzkin
authors.forename: Francesco
authors.initials: F
authors.lastname: Montorsi
mesh_terms: D000293:Adolescent; D000328:Adult; D006304:Health Status; D006801:Humans; D008297:Male; D010410:Penile Erection / Q000187:drug effects*; D010726:Phosphodiesterase Inhibitors / Q000008:administration & dosage / Q000494:pharmacology*; D010879:Piperazines / Q000008:administration & dosage / Q000494:pharmacology*; D011687:Purines; D000068677:Sildenafil Citrate; D013450:Sulfones; D011795:Surveys and Questionnaires; D013997:Time Factors
chemical_list: D010726:Phosphodiesterase Inhibitors; D010879:Piperazines; D011687:Purines; D013450:Sulfones; D000068677:Sildenafil Citrate