Impotence, or erectile dysfunction (ED), is the inability to achieve and sustain an erection for satisfactory intercourse. For an erection to occur, three conditions are required: firstly, the nerves to the penis need to function correctly; secondly, there must be an appropriate blood supply to the penis; and finally, there needs to be a stimulus from the brain. If there is a problem with any of these three things, then it will not be possible to achieve and maintain a full erection.
The incidence of impotence increases with age and episodes are common in around 50% to 55% of men between 40 and 70 years of age. Although men may worry about any episode of impotence, medically it is not unusual for a full erection to be unachievable 20% of the time. However, if there is a problem on more than 50% of occasions, the chances are that treatment may be required.
Nerve Disorders and Impotence
Injuries involving nerves, such as spinal cord and pelvic injuries, or even nerve damage caused by surgery performed on the prostate or bladder, can cause impotence. Conditions such as multiple sclerosis (MS), Parkinson’s disease and diabetes can also result in impotence. In people with diabetes, the nerves become damaged (diabetic neuropathy) due to the high levels of glucose circulating in the blood.
Restriction of Blood Supply and Impotence
Blood supply can be restricted through atherosclerosis. This condition causes arteries to narrow, preventing adequate blood flow. High blood pressure, smoking, alcohol, lack of exercise and high cholesterol levels all contribute to restricting blood flow.
Psychological factors, such as anxiety, depression, low self-esteem and fear of sexual failure can cause impotence. Even when impotence has a known physical cause, psychological factors can make it worse. If there is a psychological cause to the impotence, the chances are that the problem will develop quickly.
Other Causes of Impotence
In those who are obese, there is a greater (around 30%) chance of impotence occurring. Medications such as antidepressants, beta-blockers and water tablets (diuretics) can also cause or exacerbate the condition. Men who spend their spare time cycling may find that they also suffer from impotence, probably due to pressure on the nerves from sitting on the saddle for long periods.
Occasionally, low levels of testosterone may contribute to impotence and a small percentage of men may have anatomical abnormalities, some of which may be correctable by surgery.
This involves a physical examination to check for underlying problems as well as a discussion about lifestyle and sexual history. The doctor will usually take blood samples to check a variety of things, including cholesterol levels. Levels of prostate-specific antigen (PSA) are checked as these indicate prostate problems. The doctor may also check for evidence of diabetes with a urine test and may sometimes request other tests, such as measuring hormone levels.
Treatment for impotence usually commences with the least invasive approach. Lifestyle changes such as quitting smoking, cutting down on alcohol, losing weight and increasing the amount of exercise taken can help some men to regain full sexual function. Professionals will also assess any medication currently taken to determine whether this is causing or contributing to the impotence. They will subsequently review them to see if there are other options. Psychological support is sometimes available to those who are suffering with stress, depression or other similar problems.
The doctor or specialist may then prescribe medication. These prescription-only medications are known as PDE5 inhibitors and work by blocking the PDE5 (phosphodiesterase-5) enzyme. This allows the smooth muscle of the penis to relax, allowing blood flow to increase. Viagra (Sildenafil) and new medicines Cialis (Tadalafil) and Levitra (Vardenafil) are the three medications used to treat impotence.
Viagra is suitable as a daily drug to provide background stimulation, whereas Levitra and Cialis are longer lasting and can be taken on alternate days to maintain background stimulation. It usually takes around six weeks to assess how effective these medications are in treating impotence.
These treatments are only suitable for men who have impotence. They are not for those who wish to improve sexual performance. They will not increase libido (sexual desire), ejaculation or fertility.
PDE5 inhibitors are unsuitable for a number of men, including those who have severe heart disease, low blood pressure or uncontrolled high blood pressure or diabetes, as well as anyone who has had a stroke. PDE5 inhibitors can also interact with other medicines such as nitrates (taken for some heart conditions) and antibiotics.
Common side effects of Viagra, Cialis and Levitra during use include headaches, upset stomach and facial flushing. Some men may suffer with blurred vision or sensitivity to light.
Other treatments for impotence include self-administered injections of prostaglandin E1, which allow for the achievement of a natural erection. There are also a range of physical solutions such as vacuum erection assistance devices (VEDs) available. Some men may be prescribed hormone treatments to adjust hormone levels in the body.
Major and invasive treatments include a penile prosthesis, which is usually a last option in severe cases. Vascular surgery or angioplasty can reconstruct blood vessels and for those who are obese, surgery such as gastric-band or gastric-bypass procedures will assist in weight loss.
How long before intercourse should Viagra, Cialis or Levitra be taken?
PDE5 inhibitors are only effective with sexual arousal and need to be taken around one hour before anticipated intercourse. It is recommended that only one tablet per day is taken.
Can Viagra sustain an erection for a long time?
Any medications for impotence can sustain an erection for a long period. If an erection is sustained for more than four hours, medical advice should be sought as there is a risk of serious harm.
Are Viagra, Cialis or Levitra only available on prescription?
Up to 20% of patients are eligible for PDE5 inhibitors on prescription. This is because they are suffering from certain conditions, such as spinal cord injury, prostate cancer or neurological disorders. Otherwise, a private prescription is available from the doctor or specialist.