Erectile Dysfunction (ED), Impotence : Causes, Symptoms, Diagnosis, & Treatment

Erectile Disorder, Impotence, Erectile Dysfunction (ED) : Definition, Causes, Symptoms, Signs, Tests,  Diagnosis, Treatment (Medicines, Exercise), Prevention


  • Erectile Dysfunction (ED) refers to a persistent inability to develop or maintain an erection sufficient for sexual performance.
  • Although erectile dysfunction is not a life-threatening condition, it has a significant impact on the quality of life of patients and their partners.


Primary ED Secondary ED
Erection Never had erection Had erection once
Causes Always Organic Psychogenic > Organic
Early morning erection Absent if present: Psychogenic
if absent: Organic


Psychogenic Organic
Anxiety (Most common pyschogenic cause) e.g. performance anxiety Vasculogenic disorders (Most common organic cause) e.g., Cardiovascular disease, clogged blood vessels (atherosclerosis), high cholesterol, high blood pressure
Depression Drugs (e.g., SSRIs, β blockers, α-2 adrenergic receptor agonists, thiazides, hormone modulators, 5α-reductase inhibitors)
Sleep disorders Neurogenic disorders (e.g., diabetic neuropathy, temporal lobe epilepsy, multiple sclerosis, parkinson’s disease, multiple system atrophy
Cavernosal disorders (e.g., Peyronie’s disease)
Hyperprolactinemia (e.g., prolactinoma)
Kidney failure
Surgery (e.g., radical prostatectomy)
Lifestyle habits e.g. smoking, alcoholism
Metabolic X  syndrome, Obesity

Clinical Features

  • Trouble getting an erection
  • Trouble keeping an erection


1. Initial assessment

Complete medical history including sexual history

Physical examinations

2. Laboratory investigations

  • Serum lipids
  • Fasting plasma glucose or ideally HbA1c or IFCC
  • Serum testosterone measured on a blood sample taken in the morning
  • Serum prostate-specific antigen (PSA)

3. Specialized investigations: Most patients do not need further investigations unless specifically indicated.

  • Ultrasonography (Penile ultrasonography) : Duplex ultrasound of penile arteries
  • Penile nerves function
  • Nocturnal penile tumescence and rigidity (NPTR)
  • Penile biothesiometry
  • Intracavernous injection test
  • Dynamic infusion cavernosometry or cavernosography (DICC)
  • Corpus cavernosometry
  • Magnetic resonance angiography (MRA), Arteriography


  • An unsatisfactory sex life
  • Stress or anxiety or depression
  • Embarrassment or low self-esteem
  • Relationship problems
  • Infertility



  • The primary goal of management of ED is to enable the individual or couple to enjoy a satisfactory sexual experience.


Treatment is based upon

  • Identifying and treating any curable causes of erectile dysfunction.
  • Initiating lifestyle change and risk factor modification.
  • Providing education and counselling to patients and their partners.

Treatment modalities are as following:

A. First line

1. PDE5 Inhibitors e.g. Sildenafil, Vardenafil, Tadalafil, Avanafil

Dose Food restrictions How long before sex is tablet taken? How long is it effective for Most common side effects
Sildenafil (Viagra)
Tab 25, 50, 100 mg May take longer to work if taken with food Approx 1 h  Up to 4–5 h Headache,
Vardenafil (Levitra)
Tab 5, 10, 20 mg Can be taken with or without food, however if taken with high fat meal it may take longer to work Approx 25–60 min Up to 4–5 h Headache,
Avanafil (Spedra) Tab 50,100, 200 mg No food restriction 30 mins Up to 6 h Headache, flushing,
nasal congestion
Tadalafil (Cialis)
Tab 2.5mg OAD, 5mg
OAD, 10 & 20 mg
Can be taken with or without food At least 30min Up to 36 h Headache, dyspepsia
  • Action: Drugs that inhibit PDE5 increase arterial blood flow, which leads to smooth muscle relaxation, vasodilation and penile erection.
  • Contraindications: Organic nitrates including nicorandil are absolute contraindications with PDE5i inhibitors due to unpredictable falls in the blood pressure and, potentially, catastrophic hypotension.
  • Success rate: ∼ 75% in general {Diabetes=50–55%, After nerve-sparing radical prostatectomy=37–41%}

Non-responders to PDE5 inhibitor

Approximately 25% of patients do not respond to PDE5 inhibitors. Patients should be exposed to a minimum of 4 (preferably 8) of the highest tolerated dose of at least two drugs with adequate sexual stimulation.

Several measures are to be taken in such patients:

  1. Re-counselling on proper use, especially the need for direct genital stimulation.
  2. Optimal treatment of concurrent diseases and re-evaluation fo new risk factors.
  3. Testosterone for concurrent hypogonadism: Testosterone regulates the responsiveness of PDE5 inhibitors in the corpus cavernosum.
  4. Occasionally patients may respond to one drug when another has failed.
  5. More frequent or daily dosing.
  6. L-Arginine 2–3 g daily – a nitric oxide precursor.
  7. Folic acid 5 mg daily to enhance the effect of PDE5 inhibitors.

2. Vacuum erection devices

  • Principle: Cylinder placed over penis → air is pumped out with an attached pump → tumescence maintained by a constriction ring around the base of the penis.
  • Patient selection is vital
  • Needs several hours training
  • Highly effective regardless of the aetiology of the ED.
  • Satisfaction rates: Variable from 35% to 84%.
  • Long-term usage of vacuum devices > self-injection therapy.
  • Adverse effects: Bruising, local pain, failure to ejaculate, penis feels cold.
  • Contraindication: Men with bleeding disorders or those taking anticoagulant therapy.
  • Useful in post RP and peyronies
  • Rx under schedule II

3. Psychosexual counselling and therapy if psychogenic cause

4. Alprostadil cream: Formulation of 300mcg of alprostadil (Vitaros), applied to the glans and urethra.

B. Second line

1. Intracavernous injection therapy e.g. Alprostadil, VIP 25mcg/Phentolamine 2mg mixture

Inj. Alprostadil

  • Dose: 5-40 mg
  • The erection occurs typically 5–15min after penile injection and frequently last 30–40 min.
  • Side effects: Pain 20%, Priapism < 1%
  • Training/Dexterity required
  • Disadvantage: High discontinuation

2. Intraurethral alprostadil

  • Dose: 125–1000 mg
  • Good erection of glans
  • Needs stimulation
  • Efficacy: Modest
  • Side effects:  Pain and irritation
  • Disadvantage: High discontinuation

C. Third line

1. Penile prosthesis

  • Penile prostheses should be offered to all patients who are unwilling to consider, failing to respond to or unable to continue wit medical therapy or external devices.
  • Penile prostheses are particularly suitable for those with severe organic ED, especially if the cause is Peyronie’s disease or post priapism.
  • All patients should be given a choice of either a malleable or inflatable prosthesis.
  • Satisfaction rates: ∼ 89%


The best way to prevent erectile dysfunction is to adopt healthy lifestyle habits and to manage any existing health conditions.


  • Consult your doctor if any underlying health condition exists e.g., diabetes.
  • Stop smoking, limit or avoid alcohol.
  • Stop substance abuse.
  • Take good diet.
  • Exercise, particularly aerobic type, regularly.
  • Consult psychiatrist to get help for anxiety, depression or other mental condition if any.
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