The etiology of erectile dysfunction and mechanisms by which drugs improve erection.

Following the National Institutes of Health (NIH) consensus conference in 1988, erectile dysfunction is defined as the consistent inability to maintain a penile erection sufficient for adequate sexual relations (1). The advances in basic and clinical research during the last two decades have led to the development of several new treatment options for erectile dysfunction, including new pharmacological agents for intracavernosal, intraurethral and oral use. The recent advent of medical therapy and the poor results of long-term follow-up in reconstructive vascular surgery, have significantly modified the medical management of this disorder. Discussion of erectile dysfunction has increased, information about erectile dysfunction is increasingly available, training in erectile dysfunction was improved and last, but not least, the number of patients seeking help for erectile dysfunction is growing, because satisfactory sexual function is an important part of a couple's healthy relationship and ongoing quality of life.