Impotence in kidney disease

Dialysis USA 3-2007 004 (Photo credit: jimforest)

Approximately 50% of uremic men complain of impotence or erectile dysfunction. An even larger proportion of patients also complain of decreased desire for sex as a result of kidney disease, this is particularly so among patients in stage 5 chronic kidney disease on dialysis.

The reason for this high incidence is related to the associated diseases that are frequently present in patients on dialysis as well as the physiologic alterations that occur because of chronic kidney disease on a vascular and hormonal level. Diabetes mellitus and hypertension are the two most common predisposing causes for chronic kidney disease. Both disease conditions are associated with dysfunction of the blood vessels with an impairment of the ability to relax when needed. This affects the blood vessels within the penis as well resulting in decreased blood flow in this organ due to impaired relaxation in response to appropriate sexual stimulus.

Chronic kidney disease results in several co-morbidities, in my opinion the two most important of these are cardiovascular disease and anemia. They are both related to CKD as well as to each other. The presence of cardiovascular disease in CKD is due in part to the extreme inflammatory state that occurs in patients with kidney disease as well as due to in the increased workload carried by the heart due to retention of fluid in the presence of a decreased supply of oxygenated blood due to anemia. Anemia on the other hand is due to decreased production of erythropoietin by the kidney. This hormone is essential for the the stimulation of bone marrow to produce red blood cells which are the primary constituent of blood.

The desire for sex in men on hemodialysis increases when anemia is treated, this is caused by increased energy levels and individuals perceive themselves as being more vital and they feel "less sick" when the blood count is elevated to about 10 mg/dl by treatment with drugs such as Epogen or CERA. It has been shown in some studies that testosterone levels may also be linked to the treatment of anemia in CKD with increased levels correlating with higher blood counts.

The evaluation of this complex disorder must also include psychological testing. However the efficacy of psychotherapy which essentially is talking about the problem and working through any issues which may be preventing performance is unknown. The use of antidepressant medication for this indication in dialysis patients is not well studied and there are significant possibilities of negative drug to drug interactions along with nebulous required dose adjustments due to renal failure and dialysis to complicate matters. The use of various other methods such as direct injection of the penis with drugs to increase blood flow to the area or surgical prosthesis is certainly possible but may not be socially acceptable as many men find injection of the penis or any surgery in that area distasteful.

The real success story of the treatment of erectile dysfunction in patients with chronic kidney disease is Viagra. Sildenafil the active ingredient in viagra increases nitric oxide levels which result in powerful vasodilation. The drug specifically targets nitric oxide production in penile blood vessels thus preventing systemic vasodilation and resulting severe hypotension (low blood pressure).

Since one of the primary causes of erectile dysfunction in chronic kidney disease is decreased relaxation this treats the cause directly in the majority of patients with good effect.



photo credit: Felixe

So an approach centered around ensuring the patient is well enough for sex, treating anemia hence improving libido, adequate dialysis if on dialysis with counselling aimed at identifying and removing psychological factors which may impair performance. And if necessary prescription of Viagra or Equivalent sildenafil like compound, will be likely to produce very good results.