Background Information
Definition
ED is defined as the persistent inability to attain and maintain an erection sufficient to permit satisfactory sexual performance.
Note that erectile dysfunction is a symptom, not a disease.
Aetiology
Aetiology of ED is traditionally classified into:
- Organic, and
- Psychogenic
However, most cases of ED are actually of mixed aetiology.
Organic Causes
| Vasculogenic – most common |
|
| Neurogenic | Peripheral causes
Central causes
|
| Hormonal |
|
| Anatomical |
|
| Trauma |
|
| Drug-induced |
|
Psychogenic Causes
| Generalised |
|
| Situational |
|
Diagnosis
ED itself is a clinical diagnosis, investigations are performed to identify underlying causes of ED
History Taking
ED-focused history taking that differentiates between organic and psychogenic causes:
| History Domain | Key questions to ask | Suggests organic ED | Suggests psychogenic ED |
|---|---|---|---|
| Onset | “When did the problem start?” | Gradual, progressive onset | Sudden onset |
| Course | “Has it been getting worse over time?” | Progressive deterioration | Fluctuating, intermittent |
| Situational vs Global | “Does it happen in all situations or only with a partner?” | Present in all settings (all partners and masturbation) | Situation-specific (e.g. only with a specific partner, or only with partner but normal with masturbation) |
| Morning Erections | “Do you still get morning erections?” | Absent or reduced | Preserved |
| Libido (sexual desire) | “Has your sex drive changed?” | Reduced libido | Normal libido |
| Erection Quality | “Is it difficult to get an erection or to maintain one?” | Both initiation and maintenance affected | Usually maintenance issue |
| Ejaculation / Orgasm | “Any issues with ejaculation or orgasm?” | May be abnormal | Usually normal |
| Psychological stressors | “Any recent stress, anxiety or relationship issues?” | May coexist but not primary | Strong association |
| Performance anxiety | “Does worrying about performance make it worse?” | Minimal effect | Key feature |
A validated questionnaire related to ED should be used to assess all sexual function domains (e.g. International Index of Erectile Function) and the effect of a specific treatment modality
Cardiovascular Risk Assessment
Patients who seek treatment for sexual dysfunction have a high prevalence of cardiovascular disease:
- ED significantly increases the risk of cardiovascular disease, coronary heart disease, stroke, atrial fibrillation, cardiovascular and all-cause mortality
- ED should be considered a precursor of CVD
Therefore, it is important to perform cardiovascular risk assessment in ED patients with no overt disease or cardiac symptoms
Assess the cardiac risk of sexual activity. High risk is defined as ANY of the following:
- Unstable or refractory angina
- Recent MI (within the last 2 weeks)
- Reduced ejection fraction heart failure (NYHA class IV)
- Uncontrolled hypertension
- High-risk arrhythmia (exercise-induced ventricular tachycardia, implanted internal cardioverter defibrillator with frequent shocks, and poorly controlled atrial fibrillation)
- Hypertrophic obstructive or other cardiomyopathy
- Moderate-to-severe VHD
If the patient is considered high cardiac risk of sexual activity, all sexual activity should be stopped until specialist assessment
Physical Examination
All patients should be given a physical examination focused on:
- Genitourinary system – check for penile structural abnormalities, testicular abnormalities
- Endocrine system – check for signs of hypogonadism (e.g. testicular atrophy, alterations in secondary sexual characteristics, sparse body hair, gynaecomastia, reduced muscle mass)
- Cardiovascular system
- Neurological system – check for neuropathy
The following should be measured / assessed:
- Heart rate
- Blood pressure
- BMI or waist circumference
Laboratory Testing
Testing for ALL patients:
- Fasting blood glucose or HbA1c
- Lipid profile
- Fasting serum total testosterone (9-11 am)
If serum testosterone is low or borderline:
- Repeat serum testosterone, and
- Measure LH, FSH, SHBGSex hormone binding globulin, prolactin level
Additional investigations to consider, depending on the underlying cause and clinical judgement:
| FBC | Anaemia can contribute to reduced libido |
| U&E | CKD is associated with ED |
| LFTs | Chronic liver disease is associated with ED |
| TFTs | Both hyper- or hypothyroidism can cause ED |
| PSA | If prostate cancer is suspected |
Advanced Work-Up Tests
The following are NOT routinely necessary, and are only performed in secondary care:
- Psychopathological and psychosocial assessment – for psychogenic ED
- Nocturnal penile tumescence and rigidity test – objectively differentiate between organic and psychogenic ED (patients with psychogenic ED usually have normal findings in the NPTR test)
- Intracavernous injection test
- Dynamic duplex ultrasound of the penis – usually used if vasculogenic aetiology is suspected
- Arteriography and dynamic infusion cavernosometry or cavernosography – only in patients who are being considered for penile revascularisation
Management
Referral Criteria
| Speciality of referral | Indication |
|---|---|
| Urology | ANY of the following:
|
| Cardiology | ANY of the following:
|
| Endocrinology | ANY of the following:
|
Primary Care Management
Conservative / General Management
Before offering any therapeutic options:
- Identify and treat curable causes of ED
- Advice on lifestyle changes and risk factor modifications
- Provide education and counselling to the patient +/- their partner
Pharmacological Management
1st line: PDE-5 inhibitor (sildenafil / tadalafil / vardenafil / avanafil)
- MoA: PDE normally breaks down cGMP → prolonge cGMP-mediated smooth muscle relaxation in the corpora cavernosa
- Typically taken intermittently (15-60 min before sexual activity), as needed
- Tadalafil (long acting: up to 36 hours) may be prescribed once daily in specific circumstances
Key contraindications of PED-5 inhibitors:
- Regular / intermittent use of nitrates (due to risk of hypotension)
- Hypotension
- Recent myocardial infarction / stroke
- Unstable angina or angina occurring during sexual intercourse
Arrange follow-up 6–8 weeks after starting treatment
- If initial treatment is ineffective:
- Reassess for underlying causes and risk factors, and manage appropriately
- Note that hypogonadism and a low testosterone level may result in a reduced response or non-response to PDE-5 inhibitors
- Ensure it is taken correctly and advise on possible dose and drug regimen changes
- Suggest a trial of at least two different PDE-5 inhibitors taken sequentially before being classed as a ‘non-responder’
Patients who fail to respond to the maximum dose of at least two different PDE-5 inhibitors should be referred to a specialist
Do not recommend the use of unlicensed herbal preparations or complementary medicines.
Secondary Care Management
Options include:
- Alprostadil penile intracavernous injections
- Vacuum erection assistance devices
- Medicated urethral system for erection
- Vascular surgery/angioplasty
- Penile prostheses
References
NICE BNF Treatment summaries Erectile dysfunction
EAU Sexual and Reproductive Health Guidelines 5. Management of Erectile Dysfunction