Erectile Dysfunction


Erection requires an intact parasympathetic reflex at S2 and S3.
Ejaculation requires an intact sympathetic L1 root.
Mnemonic: Erection & ejaculation = Point & Shoot (Para & Sym)


Organic causes

  • Spinal cord or cauda equine disease
  • Multiple sclerosis
  • Endocrine disease
    • DM
    • Hypogonadism
    • Hyperprolactinaemia
  • Generalised vascular disease
  • Trauma causing nerve or vascular disease
  • Hypertension or hypertensive drugs

Psychological causes

  • Depression
  • Relationship problems
  • Sexual orientation uncertainties

Age-related problems (>50) tend to follow a common vicious circle:



  • ED occurs in 52% of men aged 40-70:
    • 17% have minimal ED
    • 25% have moderate ED
    • 10% have complete ED



All patients should have a random plasma glucose or urinalysis for glucose to exclude diabetes. Further tests to consider include:

  • Serum testosterone, prolactin, LH, sex hormone binding globulin
  • TFTs
  • FBC
  • LFTs, gamma GT, renal function, fasting lipid profile



Anxiety-induced ED is treated using a therapeutic regimen based:

  • Sexual history
  • A period of abstention for several weeks
  • Onset of therapy


Pharmaceutical treatments include

  • Phosphodiesterase-5 inhibitors eg. Sildenafil citrate (Viagra), tadalafil, verdenafil
  • Sublingual apomorphine
  • Intracavernosal injections
  • Transurethral alprostadil
  • External devices
  • Surgery

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