title: Management of sildenafil treatment failures.
abstract: OBJECTIVE
  Although oral type 5 phosphodiesterase inhibitors are considered as first-line therapy for the majority of causes of erectile dysfunction, because of their high efficacy, ease of use, and acceptable safety profile, there are some who fail to respond, mainly because of end-organ failure. This communication reviews the management of sildenafil failures in light of recent advances.
  
  
  RESULTS
  Sildenafil failures can be attributed to either lack of efficacy or side effects; issues may involve the physician, patient, and his partner. Physicians may contribute to sildenafil failure and discontinuation because of inadequate instructions, lack of adequate follow-up, suboptimal dosing, lack of adequate trial, and insufficient clarification about safety issues. Studies have demonstrated that progression of endothelial dysfunction and diminished cavernosal smooth-muscle content are recognized organic factors which cause end-organ dysfunction and ultimately treatment failure.
  
  
  CONCLUSIONS
  Proper counseling, medication optimization, and modifying associated risk factors can provide success in men who had initially failed sildenafil therapy for erectile dysfunction. Other treatment modalities that may be considered when sildenafil failure occurs include vacuum devices, intraurethral, and intracavernosal administration of vasoactive drugs alone or combined with sildenafil. Penile prosthesis implantation is considered as a last resort, if all first-line and second-line therapies fail.
authors.affiliation: Department of Urology, Sisli Etfal Training and Research Hospital, Istanbul 34280, Turkey. mkendirci@superonline.com
authors.forename: Muammer
authors.initials: M
authors.lastname: Kendirci
authors.forename: Orhan
authors.initials: O
authors.lastname: Tanriverdi
authors.forename: Landon
authors.initials: L
authors.lastname: Trost
authors.forename: Wayne J G
authors.initials: WJ
authors.lastname: Hellstrom
mesh_terms: D003376:Counseling; D004305:Dose-Response Relationship, Drug; D004351:Drug Resistance; D007172:Erectile Dysfunction / Q000188:drug therapy* / Q000503:physiopathology / Q000523:psychology; D006801:Humans; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000503:physiopathology; D019935:Penile Implantation; D010879:Piperazines / Q000009:adverse effects / Q000494:pharmacology*; D011687:Purines; D000068677:Sildenafil Citrate; D013450:Sulfones; D017211:Treatment Failure; D014665:Vasodilator Agents / Q000009:adverse effects / Q000494:pharmacology*
chemical_list: D010879:Piperazines; D011687:Purines; D013450:Sulfones; D014665:Vasodilator Agents; D000068677:Sildenafil Citrate