title: Efficacy and safety of tadalafil 20 mg on demand vs. tadalafil 5 mg once-a-day in the treatment of post-radiotherapy erectile dysfunction in prostate cancer men: a randomized phase II trial.
abstract: BACKGROUND
  The role of phosphodiesterase type 5 inhibitors in the treatment of post-radiotherapy erectile dysfunction (ED) has not been extensively investigated.
  
  
  OBJECTIVE
  To compare the efficacy and safety of on-demand 20-mg tadalafil (arm A) with the newly released tadalafil 5-mg once-a-day dosing (arm B) in patients with ED following radiotherapy for prostate cancer (PC).
  
  
  METHODS
  Randomized study to receive on-demand 20-mg or once-a-day 5-mg tadalafil for 12 weeks. Main Outcome Measures.  Changes in the International Index of Erectile Function (IIEF) domain scores and Sexual Encounter Profile (SEP) question 2 and 3 positive response rates.
  
  
  RESULTS
  Fifty-two out of 86 screened patients were randomized. Forty-four patients were evaluable for efficacy. A significant improvement in all domains of the IIEF was observed in both arms (P = 0.0001) with mean erectile function domain scores values of 25 and 27.1 for the 20-mg and 5-mg tadalafil, respectively (P = 0.19). SEP 2 and 3 positive response rates increased from 0% in both arms at baseline to 81% and 70% in the 20-mg arm and 90% and 73% in the 5-mg arm, respectively, at the end of treatment (P = 0.27). End of treatment global efficacy question positive answers were 86% in the 20-mg arm and 95% in the 5-mg arm (P = 0.27). Higher treatment compliance was shown in arm B (100%) as compared with arm A (86%). There was a nonstatistically significant trend toward fewer side effects in favor of the 5-mg daily dose arm.
  
  
  CONCLUSIONS
  In the study population, both tadalafil formulations generated significantly high response rates according to the outcome measures and were well tolerated. The once-a-day 5-mg dosing showed higher compliance and marginally reduced side effects, thus making it an attractive alternative to on-demand therapy for ED in post-radiotherapy PC patients.
authors.affiliation: University of Torino, S. Giovanni Battista Hospital, Department of Medical and Surgical Sciences, Radiation Oncology Unit, Turin, Italy.
authors.forename: Umberto
authors.initials: U
authors.lastname: Ricardi
authors.forename: Paolo
authors.initials: P
authors.lastname: Gontero
authors.forename: Patrizia
authors.initials: P
authors.lastname: Ciammella
authors.forename: Serena
authors.initials: S
authors.lastname: Badellino
authors.forename: Franco
authors.initials: F
authors.lastname: Valentino
authors.forename: Fernando
authors.initials: F
authors.lastname: Munoz
authors.forename: Alessia
authors.initials: A
authors.lastname: Guarneri
authors.forename: Nadia
authors.initials: N
authors.lastname: Rondi
authors.forename: Francesco
authors.initials: F
authors.lastname: Moretto
authors.forename: Andrea Riccardo
authors.initials: AR
authors.lastname: Filippi
authors.forename: Riccardo
authors.initials: R
authors.lastname: Ragona
authors.forename: Alessandro
authors.initials: A
authors.lastname: Tizzani
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002243:Carbolines / Q000008:administration & dosage* / Q000009:adverse effects; D003692:Delayed-Action Preparations; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D007172:Erectile Dysfunction / Q000188:drug therapy* / Q000523:psychology; D006801:Humans; D008297:Male; D055118:Medication Adherence / Q000523:psychology; D008875:Middle Aged; D009367:Neoplasm Staging; D010410:Penile Erection / Q000187:drug effects / Q000523:psychology / Q000528:radiation effects; D058986:Phosphodiesterase 5 Inhibitors / Q000008:administration & dosage* / Q000009:adverse effects; D011471:Prostatic Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D011832:Radiation Injuries / Q000188:drug therapy* / Q000523:psychology; D020266:Radiotherapy, Conformal / Q000009:adverse effects*; D000068581:Tadalafil
chemical_list: D002243:Carbolines; D003692:Delayed-Action Preparations; D058986:Phosphodiesterase 5 Inhibitors; D000068581:Tadalafil