Sildenafil has been demonstrated to improve erectile function in diabetic patients, hypertensive patients, post–transurethral resection of the prostrate patients, radical prostatectomy patients following radiation therapy for prostate cancer, geriatric patients, spinal cord injury patients, and depression patients. As many as 66-90% of patients with ED secondary to brachytherapy or external beam radiation therapy for prostate cancer have significant improvements in erectile function. For some couples sex therapy may be necessary to help you and your partner cope. It may also help you to hear from some men who have ED and learn about their experiences. Contact your doctor about local support groups in your area. Cheapest viagra without prescription 150mg viagra online without prescription Psychiatrist. Psychologist. Certified licensed social worker. looking for cheap viagra online? 100mg viagra online without prescription A. While the injections have a high success rate (over 70 percent), the drugs may not be able to override poor blood flow to the penis. In some cases, the trimix may produce an initial erection, but venous drainage (inability of penile tissues to trap blood) in the penis allows blood to escape rapidly, resulting in an unsustainable erection. An erection occurs as a hydraulic effect due to blood entering and being retained in sponge-like bodies within the penis. The process is most often initiated as a result of sexual arousal, when signals are transmitted from the brain to nerves in the pelvis. Erectile dysfunction is indicated when an erection is consistently difficult or impossible to produce, despite arousal. There are various and often multiple underlying causes, some of which are treatable medical conditions. The most important organic causes are cardiovascular disease and diabetes, neurological problems (for example, trauma from prostatectomy surgery), hormonal insufficiencies (hypogonadism) and drug side effects. It is important to realize that erectile dysfunction can signal underlying risk for cardiovascular disease.