Efficacy and Safety of Tadalafil in Subjects With Erectile Dysfunction Caused by Spinal Cord Injury

Inclusion Criteria: * males who developed erectile dysfunction as a result of spinal cord injury. Injury must have occurred 6 months before the start of the study. * at least 4 sexual intercourse attempts during the first 4 weeks of the study without medication assistance * no use of other erectile dysfunction treatment for at least 4 weeks before receiving the first dose of study drug. Also cannot use any other erectile dysfunction treatment during the study. Exclusion Criteria: * Impotence caused by other primary sexual disorders including premature ejaculation or untreated endocrine diseases such as diabetes, hypopituitarism, hypothyroidism, or hypogonadism * History of radical prostatectomy or other pelvic surgery with subsequent failure to achieve any erection and history of penile implant. * History of cardiac conditions including angina requiring certain treatment with nitrates; heart disease or coronary conditions including myocardial infarction, bypass surgery, angioplasty or stent placement for a specified time before starting the study. * Significant renal problems within 6 months before starting the study. Also, active liver disease including jaundice at beginning of study. * History of other central nervous system injuries, other than spinal cord injury, 6 months before starting the study.