Is there a common pathophysiology of erectile dysfunction and how does this relate to new pharmacotherapies?

Many basic and clinical studies show erectile dysfunction (ED) to be caused by a wide variety of factors. Although these factors can be divided into psychological and organic origins and these too can further be subdivided, many patients will show complex patterns of causes for ED ('mixed ED'). Many of these factors will have a direct or indirect impact on the efficacy of centrally and peripherally acting drugs, thus necessitating a variety of drugs with different modes of action and different modes of application to ensure appropriate therapy for many patients. However, some factors will render all imaginable forms of pharmacological options totally inefficient, thus necessitating forms of treatment other than pharmacotherapy.