Synonym: impotence (no longer used, as it implies failure)
Erectile dysfunction (ED) is the inability to attain and maintain an erection sufficient for satisfactory sexual performance. Although a benign disorder, it can have a significant impact on the quality of life of sufferers, partners and families. It is important also to consider the physical and psychosocial health of the sufferer. Patients should be properly assessed and investigated before embarking on treatment.
- The incidence and prevalence is high worldwide.
- The first large-scale community study - the Massachusetts Male Ageing Study - showed that 52% of men (aged 40 to 70 years) were affected at some time (mild 17%; moderate 25%; severe 10%).
- A Cologne study reported that ED was the most prevalent of the male sexual dysfunctions (prevalence age 30 to 80 years) at 19.2% as compared to 31% for all types of male sexual dysfunction. This study equates to about 26 new cases annually per 1,000 men. Whichever study, country or methodology is used, this is clearly a significant condition likely to present regularly to a GP on average between 1 and 4 times per month. Significant media interest has led more men to seek help for ED.
- There is in all studies a steep age-related increase. The Cologne study found that of men aged 30-80 years, the prevalence rose from 2.3% at age 30 to 53.4% at age 80. .
- Only about 10-20% of patients with erectile dysfunction are believed to have a solely psychogenic cause but psychogenic factors are often present in those who are diagnosed as having a physical cause.
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Risk factors for erectile dysfunction
ED shares risk factors with cardiovascular disease (CVD).The following are all associated with both CVD and ED:
- Lack of exercise
- Metabolic syndrome
- Diabetes mellitus
It is important that underlying diseases and causative conditions do not go undetected. There are many different causes, including many drugs:
- Vascular factors:
- Atherosclerosis (approximately 50% of cases)
- Diabetes mellitus
- Surgery or radiotherapy to the pelvis or retroperitoneum
- Central causes:
- Parkinson's disease, stroke
- Multiple sclerosis (MS)
- Traumatic brain injury (causing hypothalamic-pituitary deficiency)
- Cerebrovascular disease
- Intervertebral disc disease
- Spinal cord disease or injury
- Peripheral causes:
- Peripheral neuropathy
- Diabetes mellitus
- Surgery (for example of pelvis or retroperitoneum)
- Thyroid disease
- Cushing's disease
- Peyronie's disease
- Micropenis and other penile anomalies
- Antidepressants: both tricyclics and selective serotonin reuptake inhibitors (SSRIs)
- Antipsychotics: phenothiazines, risperidone
- Hormonal agents: cyproterone acetate, luteinising hormone-releasing hormone analogues
- Anticonvulsants: phenytoin, carbamazepine
- Recreational drugs
- H2 antagonists cimetidine and ranitidine
- Psychosexual factors:
- General (disorders of sexual intimacy, lack of arousability).
- Situational (partner, performance or stress).
- One study found that maintaining a regular frequency of intercourse can reduce the risk of ED for males aged among 30 to 75 years.
- Psychiatric illness:
- Generalised anxiety states.
- Alcoholism (the relationship with alcohol is not straightforward). A Chinese study suggested an additive association with smoking. It reported that drinking three or more standard alcoholic drinks per week might reduce sexual satisfaction and impair erectile function in current smokers and might have less effect in those who had never smoked. A meta-analysis showed a protective effect of alcohol at some levels of consumption).
- Sexual history. Validated questionnaires to assess sexual function and the effects of treatment are available - for example, the International Index of Erectile Function (IIEF). The following should be covered:
- Current and past sexual relationships
- Current emotional status
- Erectile symptoms: onset and duration
- Previous advice or treatments
- Quality of erections (erotic and morning erections)
- Arousal, ejaculation and orgasmic difficulties
- Medical and past medical history:
- This may include detail of any relevant conditions (see the causes of erectile dysfunction, above).
- Medication should be listed.
History suggesting psychogenic causes
- Sudden onset
- Early collapse of erection
- Self-stimulated or waking erections
- Premature ejaculation or inability to ejaculate
- Problems or changes in a relationship
- Major life events
- Psychological problems
History suggesting organic causes
- Gradual onset
- Normal ejaculation
- Normal libido (except hypogonadal men)
- Risk factor in medical history (cardiovascular, endocrine or neurological)
- Operations, radiotherapy, or trauma to the pelvis or scrotum
- A current drug recognised as associated with erectile dysfunction
- Smoking, high alcohol consumption, use of recreational or bodybuilding drugs
The examination should be focused and performed on all patients:
- Genitourinary examination (it is necessary to detect, for example, Peyronie's disease, gonadal anomalies, retractile foreskin).
- Attention to any endocrine (including testicular size and secondary sexual characteristics), neurological or vascular causes as appropriate, especially if indicated by the history.
- Pulse (including peripheral pulses) and blood pressure if recent readings are not available. Because ED shares risk factors with CVD, a full cardiovascular assessment should be performed.
- Rectal examination in patients over age 50 years.
Investigations will be directed by the history and clinical findings.
- The European Association of Urology and the British Society of Sexual Medicine suggest:
- Fasting glucose or HbA1c and lipid profile for all patients (if not assessed in the previous 12 months).
- Morning sample of total testosterone (free testosterone if available, as it is more reliable in detection of hypogonadism).
- Further tests (for example, PSA) only in selected patients.
- Addition of follicle-stimulating hormone (FSH), luteinising hormone (LH), and prolactin when low testosterone is detected.
- Other specific investigations may be indicated and are appropriately arranged by urologists. Indications for referral for these further tests are given below. Further tests include:
- Nocturnal penile tumescence and rigidity studies
- Vascular studies
- Duplex ultrasound cavernous arteries
- Intracavernous vasoactive drug injection
- Dynamic infusion cavernosography
- Arteriography (internal pudendal)
- Neurological studies
- Endocrinology work-up
- Specialist psychodiagnostic evaluation
Indications for referral
The following should be referred for further assessment or specific diagnostic tests:
- Endocrine abnormality.
- Referral for underlying organic disease as appropriate - eg, cardiovascular or neurological.
- Young patients who have suffered pelvic or perineal trauma.
- Penile disorders or deformities requiring possible surgical correction.
- Complex cases (whether psychiatric, cardiovascular, psychosexual or endocrine).
- If a patient of partner requests referral or special tests.
- The main aim of management is to diagnose and treat the cause of ED when possible.
- Associated modifiable or reversible factors (lifestyle, drug-related factors) should be considered as well as specific therapies.
- Most often it cannot be cured but, where appropriate, curative therapies should be offered.
- Treatments will be selected, therefore, according to efficacy, safety, invasiveness, cost and patient preference.
- With increasing longevity, the treatment of ED in the elderly has assumed greater importance. Hypogonadism should be treated with testosterone replacement, regardless of age.
- A flow chart or algorithm can be used to assist treatment plans.
Data from basic science and clinical studies have identified a link between the occurrence of ED and a number of lifestyle factors, such as smoking, obesity, alcohol consumption and lack of physical activity. Cycling for more than three hours per week has been identified as an independent risk factor for erectile dysfunction. Large-scale trials are needed to assess the place of lifestyle modification in the management of ED.
Treating the cause
The following are regarded as curable causes for ED, which can be treated:
- Hormonal causes:
- Testicular failure - treat with testosterone.
- Pituitary or hypothalamic causes - treat the underlying causes; for example, pituitary tumours causing hyperprolactinaemia.
- Post-traumatic arteriogenic ED in young patients:
- Surgery following pelvic or perineal trauma has a 60-70% success rate.
- This requires proper diagnostic work-up (including duplex ultrasound and arteriography).
- Psychosexual causes:
- Management includes the management of any specific underlying psychological problem.
- Psychosexual therapy:
- See separate article Sex Therapy and Counselling.
- A meta-analysis confirmed the effectiveness of group psychotherapy in the treatment of ED and that psychological interventions were as effective as vacuum devices and local injections.
- Psychological therapy is most effective when appropriately targeted.
- Drug treatments (eg, the phosphodiesterase type-5 inhibitors sildenafil, tadalafil or vardenafil) may be effective and sometimes need only be used short-term.
First-line therapy for erectile dysfunction
Phosphodiesterase inhibitors (sildenafil, tadalafil and vardenafil) improve the relaxation of smooth muscle. Efficacy of the drug is dependent on release of nitric oxide from the nerve terminals of the cavernosal nerve.
Sildenafil, tadalafil and vardenafil are contra-indicated in patients receiving nitrates (because of possible severe hypotension, which may lead to acute myocardial infarction, stroke and even death).
- Phosphodiesterase inhibitors are also contra-indicated in patients in whom vasodilation or sexual activity are inadvisable, and where there is previous history of non-arteritic anterior ischaemic optic neuropathy, hypotension (avoid if systolic blood pressure is below 90 mm Hg and recent stroke, unstable angina or myocardial infarction.
- There are no meta-analyses to compare the three preparations, so choice will depend on personal preference of the patient and frequency of intercourse.
- Improves erectile function and is generally well tolerated.
- Efficacy is reduced after fatty meals.
- 50 mg is the recommended starting dose (change according to response).
- Adverse events are rare and the drop-out rate similar to placebo.
- Has a longer half-life - therefore, potentially, a longer action and therefore greater spontaneity (effective after 30 minutes, with peak efficacy at two hours and lasting up to 36 hours).
- Start at 10 mg (change according to response).
- Adverse events and drop-outs similar to above.
- Better results in subgroups which are difficult to treat.
- Effective after 30 minutes.
- More potent than the other two phosphodiesterase inhibitors but not necessarily clinically more effective.
- Useful in subgroups which are difficult to treat.
- Its effect is reduced by a fatty meal but it has less interaction with food. A rapidly absorbed orodispersible preparation has now been made available which is more rapdily absorbed.
- Also used but with less proven efficacy are:
- Used for 100 years as an aphrodisiac.
- Central and peripheral actions.
- It is claimed to be a safe and effective treatment for ED.
- It has a modest effect (equivalent to placebo) on psychogenic but not organic.
- It is not licensed for NHS treatment in the UK but used as a natural remedy by many patients.
- Other oral agents with limited data and no place in the treatment of ED:
- Delequamine: similar to yohimbine.
- Trazadone: an SSRI antidepressant associated with prolonged erections and priapism.
- Red Korean ginseng (unknown mechanism).
- Limaprost is an alprostadil derivative.
- Phentolamine has a weak effect when used as monotherapy but its effect in combination with other drugs is being explored.
- An external cylinder is fitted over the penis to allow air to be pumped out, resulting in engorgement of penis with blood.
- Studies suggest that whilst two thirds of patients are unable to achieve ejaculation, 74% are able to achieve orgasm.
- They work best when there is a motivated, interested and understanding partner. They may be the treatment of choice in well-informed older patients and in those with comorbidities precluding use of drugs or invasive methods..
- Adverse events include pain, petechiae, bruising and numbness.
Second-line therapy for erectile dysfunction
Intraurethral alprostadil (prostaglandin E1):
- This is inserted as a medicated pellet called MUSE® into the urethral meatus and produces an erection after about 15 minutes.
- Barrier contraception must be used if the partner is pregnant.
- 30-65.9% of patients achieve erections sufficient for intercourse.
- However, it is less effective than intracavernous injections.
- The most common side-effect is mild penile pain (29-41% of patients).
Intracavernosal alprostadil (prostaglandin E1):
- Injections of alprostadil are given into the corpora cavernosa to produce an erection. It is licensed in the UK for a maximum dose of 40 µg. The duration of erection depends on the dose.
- Efficacy rates for intracavernous alprostadil of >70% in the general population have been reported and it is often effective for those men who do not respond to oral drug treatment.
- Penile pain (50% of patients) is usually mild but a significant number of men stop using this method because of this side-effect.
- If priapism occurs with alprostadil:
- The patient should be referred urgently to hospital.
- Patients are advised to seek medical advice if the erection has lasted longer than four hours.
- Treatment should not be delayed for more than six hours. Initial treatment is by aspiration of blood from the corpus cavernosum.
- If this is unsuccessful, cautious intracavernosal injection of a sympathomimetic (eg, phenylephrine or adrenaline (epinephrine), may be required).
- If sympathomimetics are unsuccessful, urgent surgical referral is required (possibly including shunt procedure).
Third-line therapy for erectile dysfunction
- Semi-rigid, malleable or inflatable devices surgically inserted to produce an erect state. Most patients prefer the three-piece inflatable penile prosthesis which includes a separate reservoir placed in the abdominal cavity.
- Prostheses should be considered in patients whose impotence has an organic cause and who are unwilling to consider, fail to respond to, or are unable to continue with medical treatment or external devices.
Low-intensity shock-wave therapy has shown promising results in trials in patients resistant to other treatments.
- Various vasoactive drugs in topical gel formulations are available.
- Local reactions and side-effects in the partner, from vaginal absorption, have been reported.
- None of these has been approved for use in ED treatment and so cannot be recommended.
Private or NHS prescription?
Phosphodiesterase inhibitors, apomorphine and alprostadil can only be prescribed by GPs on the NHS for men who:
- Have diabetes, MS, Parkinson's disease, poliomyelitis, prostate cancer, severe pelvic injury, single-gene neurological disease, spina bifida, or spinal cord injury.
- Are receiving dialysis for renal failure.
- Have had radical pelvic surgery, prostatectomy, or a kidney transplant.
- Were receiving Caverject®, Erecnos®, MUSE®, Viagra®, or Viridal® for erectile dysfunction, at the expense of the NHS, on 14 September 1998.
- Treatment should also be available from specialist services (under local agreement) when the condition is causing severe distress. The criteria for severe distress include:
- Significant disruption to normal social and occupational activities.
- A marked effect on mood, behaviour, social and environmental awareness.
- A marked effect on interpersonal relationships.
If the patient does not fit these criteria, a private prescription can be issued.
Further reading & references
- Lin CS, Xin ZC, Wang Z, et al; Stem cell therapy for erectile dysfunction: a critical review. Stem Cells Dev. 2012 Feb 10;21(3):343-51. doi: 10.1089/scd.2011.0303. Epub 2011 Sep 7.
- Guidelines on Male Sexual Dysfunction: Erectile dysfunction and premature ejaculation, European Association of Urology (2013)
- San Martin C, Simonelli C, Sonksen J, et al; Perceptions and opinions of men and women on a man's sexual confidence and its relationship to ED: results of the European Sexual Confidence Survey. Int J Impot Res. 2012 Nov-Dec;24(6):234-41. doi: 10.1038/ijir.2012.23. Epub 2012 Jun 21.
- Nehra A, Jackson G, Miner M, et al; Diagnosis and Treatment of Erectile Dysfunction for Reduction of Cardiovascular Risk. J Urol. 2013 Jan 9. pii: S0022-5347(13)00009-8. doi: 10.1016/j.juro.2012.12.107.
- Nehra A, Jackson G, Miner M, et al; The Princeton III Consensus recommendations for the management of erectile dysfunction and cardiovascular disease. Mayo Clin Proc. 2012 Aug;87(8):766-78. doi: 10.1016/j.mayocp.2012.06.015.
- Javaroni V, Neves MF; Erectile dysfunction and hypertension: impact on cardiovascular risk and treatment. Int J Hypertens. 2012;2012:627278. doi: 10.1155/2012/627278. Epub 2012 May 9.
- Hirooka N, Lapp DP; Erectile dysfunction as an initial presentation of diabetes discovered by taking sexual history. BMJ Case Rep. 2012 May 8;2012. pii: bcr1220115289. doi: 10.1136/bcr.12.2011.5289.
- Keller J, Chen YK, Lin HC; Hyperthyroidism and erectile dysfunction: a population-based case-control study. Int J Impot Res. 2012 Nov-Dec;24(6):242-6. doi: 10.1038/ijir.2012.24. Epub 2012 Jun 21.
- Qin Z, Tian B, Wang X, et al; Impact of frequency of intercourse on erectile dysfunction: a cross-sectional study in Wuhan, China. J Huazhong Univ Sci Technolog Med Sci. 2012 Jun;32(3):396-9. doi: 10.1007/s11596-012-0068-9. Epub 2012 Jun 9.
- Perelman MA; Erectile dysfunction and depression: screening and treatment. Urol Clin North Am. 2011 May;38(2):125-39. doi: 10.1016/j.ucl.2011.03.004.
- Lee AC, Ho LM, Yip AW, et al; The effect of alcohol drinking on erectile dysfunction in Chinese men. Int J Impot Res. 2010 Jul-Aug;22(4):272-8. doi: 10.1038/ijir.2010.15. Epub 2010 Jun 17.
- Cheng JY, Ng EM, Chen RY, et al; Alcohol consumption and erectile dysfunction: meta Int J Impot Res. 2007 May 31;.
- Rosen RC, Cappelleri JC, Gendrano N 3rd; The International Index of Erectile Function (IIEF): a state-of-the-science review. Int J Impot Res. 2002 Aug;14(4):226-44.
- Erectile Dysfunction: A GP summary guide for assessment and management; Erectile Dysfunction Working Group, Monash University, 2005
- Guidelines for Erectile Dysfunction, British Society of Sexual Medicine (2009)
- Romanelli F, Sansone A, Lenzi A; Erectile dysfunction in aging male. Acta Biomed. 2010;81 Suppl 1:89-94.
- Lamina S, Agbanusi E, Nwacha RC; Effects of aerobic exercise in the management of erectile dysfunction: a meta analysis study on randomized controlled trials. Ethiop J Health Sci. 2011 Nov;21(3):195-201.
- Melnik T, Soares BG, Nasello AG; The effectiveness of psychological interventions for the treatment of erectile dysfunction: systematic review and meta-analysis, including comparisons to sildenafil treatment, intracavernosal injection, and vacuum devices. J Sex Med. 2008 Nov;5(11):2562-74. doi: 10.1111/j.1743-6109.2008.00872.x. Epub 2008 Jun 17.
- Fonagy P; Psychotherapy research: do we know what works for whom? Br J Psychiatry. 2010 Aug;197(2):83-5. doi: 10.1192/bjp.bp.110.079657.
- Ernst E, Posadzki P, Lee MS; Complementary and alternative medicine (CAM) for sexual dysfunction and erectile dysfunction in older men and women: an overview of systematic reviews. Maturitas. 2011 Sep;70(1):37-41. doi: 10.1016/j.maturitas.2011.06.011. Epub 2011 Jul 22.
- Pinsky MR, Chawla A, Hellstrom WJ; Intracavernosal therapy and vacuum devices to treat erectile dysfunction. Arch Esp Urol. 2010 Oct;63(8):717-25.
- Costa P, Potempa AJ; Intraurethral alprostadil for erectile dysfunction: a review of the literature. Drugs. 2012 Dec 3;72(17):2243-54. doi: 10.2165/11641380-000000000-00000.
- Gruenwald I, Appel B, Vardi Y; Low-intensity extracorporeal shock wave therapy--a novel effective treatment for erectile dysfunction in severe ED patients who respond poorly to PDE5 inhibitor therapy. J Sex Med. 2012 Jan;9(1):259-64. doi: 10.1111/j.1743-6109.2011.02498.x. Epub 2011 Oct 18.
|Original Author: Dr Richard Draper||Current Version: Dr Laurence Knott||Peer Reviewer: Dr Adrian Bonsall|
|Last Checked: 12/04/2013||Document ID: 2114 Version: 23||© EMIS|
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