Erectile Dysfunction (Impotence)

Essentials

• Erectile dysfunction (ED) is defined as persistent inability to achieve and maintain penile erection that is sufficient for satisfactory sexual performance.
• ED is often of organic origin. However, problems in self confidence and couple relationship are associated with it, secondarily at least. They have to be taken into account when treating these men.
• ED often significantly decreases the patient's quality of life.
• ED may be the first sign of a cardiovascular disease.
• Primary ED of a young man has to be examined by an urologist. A general practitioner can well treat older men withED that has developed gradually.

Epidemiology

• Approximately half of men aged 40 to 70 years report of some level of erectile dysfunction.
• Erectile dysfunction is considered severe if more than 75% of attempted sexual intercourses fail.

Aetiology

• Chronic diseases
  • Systemic diseases: diabetes, hypertension, obesity, dyslipidaemias, cardiovascular diseases
  • Local factors: systemic sclerosis Systemic Sclerosis, severe Peyronie's disease Peyronie's Disease (Induratio Penis Plastica)
• Vascular factors
  • Atherosclerosis, smoking, venous leakage
• Endocrine causes
  • Testosterone deficiency
    • Elderly men may have testosterone deficiency that can be treated using testosterone or dihydrotestosterone. However, the prevalence of hypogonadism in men with erectile dysfunction varies significantly (4-35%).
    • Small testes and infertility are associated with Klinefelter's syndrome (an extra X chromosome).
  • Hyperprolactinaemia, diseases of the thyroid or pituitary gland, disorders of cortisol production
• Drugs
  • Among antihypertensive drugs, calcium channel blockers as well as ACE inhibitors and ATR blockers rarely cause erectile dysfunction, but are not completely harmless either. Untreated hypertension, on the other hand, is also associated with erectile dysfunction.
  • Digoxin, thiazide diuretics, spironolactone, beta blockers
  • Most psychopharmacological agents. Decreased libido and delayed ejaculation are also typical adverse effects of SSRIs.
  • Testosterone 5-alpha reductase drugs (finasteride, dutasteride) may cause erectile dysfunction and decrease the volume of ejaculates.
  • Antiandrogenic drugs (used in hormone therapy for prostate cancer)
• Neurological causes
  • Neuropathies: diabetic neuropathy, alcohol neuropathy, autonomic neuropathy, multiple sclerosis
  • Injuries: sequelae of pelvic traumas or operations in the pelvic area (especially prostatic surgery), spinal cord injury, etc.
  • Cycling: penile sensory loss and transient erectile dysfunction have been encountered especially in long distance cyclists. There is no clear evidence on the effects of recreational cycling (< 3 hours per week).
• Alcohol overuse
  • Erections improve in 50% of men after abstaining from alcohol.
• Psychological causes
  • Depression, mental stress, feeling nervous about the intercourse, problems in the couple relationship

Investigations in erectile dysfunction

Investigation strategy in general practice

1. Possible underlying diseases and predisposing medications are assessed. Diabetes and hypertension are treated to as a good balance as possible. A recommendation is given to stop smoking and alcohol consumption. Suspicious drugs are changed to others. A new appointment is given, for 2-3 months later.
2. If dysfunction has not improved (or when the patient would like to try the medication immediately, without the follow-up period) the following tests are carried out:
   • serum testosterone or free testosterone in all cases
   • serum prolactin, if serum testosterone concentration is decreased and, besides erectile dysfunction, sexual desire is low
   • other above-mentioned blood tests according to suspected aetiology.
3. Young men (below 40-50 years of age) without any systemic diseases are sent to a urologist after the first investigations (the cause may be operatively treatable, as in venous leakage). However, there is often no need for further investigations. A therapeutic trial with a phosphodiesterase-5 inhibitor is recommended already at this point. A general practitioner may treat older men.

Treatment Group Psychotherapy for Erectile Dysfunction

• If a man with erectile dysfunction has low serum testosterone, a normal prostate by palpation, normal plasma levels of prostate-specific antigen and lipids (should always be tested), testosterone treatment can be started. It should be kept in mind, however, that erectile dysfunction is rarely caused by low testosterone concentration even if such is found in the laboratory tests.
  • Combination of testosterone esters (Sustanon "250"^® ), 1 amp. i.m. every 3 weeks
  • Testosterone undecanoate
    • Panteston^® 40 mg × 3-5
    • Nebido^® 1 amp. i.m. every 10-14 weeks
  • Transdermal gel according to the recommended dosage
  • Follow-up
    • The size of the prostate and assay of plasma prostate-specific antigen are initially checked every half years, then at least yearly.
    • Regular check of haemoglobin, haematocrit (to detect polycythaemia), liver function tests and serum lipid profile
    • Irritability, nervousness, weight increase and prolonged or frequent erections may be signs of excessive androgen effect. In such a case the dosage has to be reduced.
    • If erectile dysfunction has not improved within a few weeks, therapy is stopped, and other causes and treatments are sought.
• Phosphodiesterase type-5 (PDE-5) inhibitorsPhosphodiesterase Inhibitors for Erectile Dysfunction, Vardenafil for Erectile Dysfunction are effective in the treatment of erectile dysfunction of different aetiologies.
  • Active agents:sildenafil, vardenafil, tadalafil and avanafil
  • There is no significant difference in the efficacy of the different drugs, but taladafil has a longer duration of action.
  • PDE-5 inhibitors enhance the blood-pressure-lowering effect of nitrates, and they should thus not be used concomitantly with nitrate preparations.
  • Contraindications include severe cardiovascular disease (e.g. cardiac failure, angina that easily becomes symptomatic), severe hepatic insufficiency, very low blood pressure, recent cerebral infarction or myocardial infarction or hereditary degenerative retinal disease.
  • The most common adverse effects include headache, flushing, dyspepsia, nasal stuffiness, transient visual disturbances, and with tadalafil muscle aches mainly at the beginning of treatment.
  • Some men with normal sexual functions want to use PDE-5 inhibitors for ”recreational purposes”. The post-ejaculatory refractory period is shortened also in healthy men using these drugs, i.e. they are able to perform new sexual intercourse more quickly. Even if knowledge on the possible adverse effects of recreational use is restricted, cerebral infarction has been described in association with sildenafil overdose.
  • PDE-5 inhibitors are the largest group of prescription drugs illegally marketed on the Internet. The Internet drugs have been shown to contain 0% to over 200% of the effective agent and various different contaminants.
• Injectable and intraurethral drugs
  • Intracavernous prostaglandin injections (alprostadil) or an intraurethral prostaglandin preparation (alprostadil) are options if oral preparations are not effective or if they are contraindicatedAlprostadil for Erectile Dysfunction.
  • Combination of aviptadil and phentolamine is a therapy for ED in injection form. Aviptadil is a vasoactive intestinal peptide (VIP) which suppresses vascular blood flow during erection. Phentolamine is an alpha-blocking agent that increases arterial blood flow in cavernous tissues. Neither drug is able to produce erection alone, but when used in combination, about 74% of patients can have an erection that enables sexual intercourse. Contraindications are similar to those of alprostadil injection therapy.
  • A test is first carried out in the clinic to see if an erection can be achieved with the injection. If this is successful the technique is taught to the patient and maybe his partner. The patient is given written instructions of the injection technique and of the management in case a prolonged erection (4-6 hours) should occur.
  • Injection technique
    • The starting dose in young men with neurogenic impotence is 0.25 ml (5 µg), in older men 0.5-1.0 ml (10-20 µg). If necessary, the dose can be increased to 2 ml (40 µg).
    • When using aviptadil/phentolamine combination, no dose titration is required, since the dose is 1 ampoule.
    • The solution is injected into the erectile tissue in the proximal third of the penis. The needle is directed obliquely downwards on either side of the penis. The urethra can hence be avoided.
    • Intraurethral alprostadil or alprostadil cream applied on the tip of penis can be tried if the injection with a needle feels awkward or difficult.
  • Adverse effects
    • Pain in the penis, in every second man, seldom severe
    • Prolonged erection (4-6 hours) in 5%
    • Priapism (requiring treatment, over 6 h) in 1%
  • Treatment of prolonged erection
    • Physical activity, for example, walking up and down stairs, cool showers
    • Blood (100-200 ml) can be aspirated from the penis by using a needle and syringe.
    • An alpha-adrenergic drug (such as Effortil^® , 5 mg (0.5 ml), or noradrenaline, 0.02-0.04 mg) can be injected into the erectile tissue, repeatedly if necessary.
    • Referral to a hospital urology unit should readily be considered.
• Penile prosthesis
  • When a penile prosthesis is implanted, the cavernous tissues are replaced with silicone cylinders that can be filled with fluid by using a pump placed in the scrotum. The fluid reservoir is placed behind the lower abdominal muscles.
  • The operation requires careful consideration.