Overview Study to Determine a Preference Between Sildenafil or Tadalafil Treatment for Problems Getting an Erection Status: Completed Trial end date: 2005-06-01 Target enrollment: Participant gender: Summary To determine if men with problems getting and keeping an erection prefer treatment with tadalafil or sildenafil. Phase: Phase 4 Details Lead Sponsor: Eli Lilly and CompanyCollaborator: ICOS CorporationTreatments: Sildenafil CitrateTadalafil