Erectile dysfunction, also known as impotence and abbreviated as ED, is a condition in which there is inability to achieve and maintain penile erection enough for sexual intercourse. It should not be confused with premature ejaculation whereby there is early emission of semen occurring just after beginning sexual intercourse, leading to flaccidity of the penis.
Most erectile dysfunction is related to vascular, neurologic, hormonal and psychologic disorders. It can also be iatrogenic whereby some drugs can result in an alteration of the normal erectile process.
It has a prevalence of more than 50% in men aged between 40-70 years. It has however been successfully manageable using drug therapy and psychotherapy for those whose main cause is psychological disturbances.
In order to properly understand erectile dysfunction, there is need to understand the physiology of the normal erectile process.
Normal Erectile Process and Pathophysiology of Erectile Dysfunction
The penis is made up of smooth muscles known as bulbocavernosus muscles. These muscles are supplied with blood by helicine arteries, and also supplied with autonomic preganglionic nerves which mediate the erectile response. During sexual excitation, there is release of chemicals knowns as nuerotransmitters from the autonomic nerve endings and a release of relaxation factors from endothelial cells lining the sinusoids in the penile smooth muscle. The major relaxation factor is nitric oxide(NO), which induces production of other relaxation factors such as cGMP and cAMP, which result in molecular changes that cause relaxation of the smooth muscles in the arteries and arterioles that supply the erectile tissue, causing a sudden increase in penile blood flow. Additional relaxation of sinusoidal smooth muscle increases its compliance, facilitating raoid filling and expansion. The venules beneath the tunica albuginea are compressed, resulting in near-total occlusion of venous outflow. This cascade results in an erection. Testosterone is also a key hormone that acts together with its metabolite dihydroteststerone to mediate erection by enhancing NO production.
ED etiology is usually divided into two broad categories, which are; organic and psychogenic. However, pure psychogenic ED is uncommon- it is usually superimposed with other organic etiologies.
Various diseases affect the erectile function by altering the nervous, vascular and hormonal systems, producing changes that affect proper function of the bulbocarvenosal smooth muscle.
Diseases such as diabetes, hypertension, coronary artery disease,neurologial disorders such as stroke, epilepsy and multiple sclerosis, COPD, depression and athersclerosis may affect erectile function.
Other risk factors for development of ED are smoking, alcohol abuse, endocrine disorders such as hypogonadism, and obesity.
Diagnosis of ED
Diagnosis involves clinical evaluation of the aforementioned risk factors, screening for depression and examination of the genitals for possible signs of hormonal, neurologic and vascular disorders.
Lab tests are also run to check on the levels of testosterone, and total blood cholesterol levels.
Treatment of ED
Fortunately enough, there are medications available for treatment of ED. After diagnosis, the doctor will evaluate on the appropriate medications to prescribe depending on the severity of ‘damage’.
The underlying causes can be treated such as diabetes, among others before rushing to prescribe drugs for ED.
Oral PDE5 inhibitors( phosphodiesterase type 5 inhibitors) such as sildenafil, avanafil, tadalafil and vardenafil can be used and taken as prescribed, usually once a day and a few minutes to an hour to sexual intercourse. Intracavernosal alprostadil can also be administered in more severe cases.
Vacuum erection devices as well as surgery can be opted for, should the aforementioned treatment plans fail.
Note that it may be dangerous to use the above drugs without the doctor’s prescription because of serious adverse effects that may ensue such as prolonged painful erections with penile fracture.
Prevention of ED
Exercise and lifestyle modifications may improve erectile function. Weight loss, avoiding risk factors such as smoking and alcohol abuse that predispose one to ED is efficient in increasing and maintaining testosterone levels.