A 69-year-old man is started on tamsulosin for benign prostatic hyperplasia

A 69-year-old man is started on tamsulosin for benign prostatic hyperplasia. Which one of the following best describes the side-effects he may experience?

Urgency + insomnia

Dizziness + postural hypotension

Urinary retention + nausea

Urgency + erectile dysfunction

Erectile dysfunction + reduced libido

Benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) is a common condition seen in older men.

Risk factors

  • age: around 50% of 50-year-old men will have evidence of BPH and 30% will have symptoms. Around 80% of 80-year-old men have evidence of BPH
  • ethnicity: black > white > Asian

BPH typically presents with lower urinary tract symptoms (LUTS), which may be categorised into:

  • voiding symptoms (obstructive): weak or intermittent urinary flow, straining, hesitancy, terminal dribbling and incomplete emptying
  • storage symptoms (irritative) urgency, frequency, urgency incontinence and nocturia
  • post-micturition: dribbling
  • complications: urinary tract infection, retention, obstructive uropathy

Management options

  • watchful waiting
  • medication: alpha-1 antagonists, 5 alpha-reductase inhibitors. The use of combination therapy was supported by the Medical Therapy Of Prostatic Symptoms (MTOPS) trial
  • surgery: transurethral resection of prostate (TURP)

Alpha-1 antagonists e.g. tamsulosin, alfuzosin

  • decrease smooth muscle tone (prostate and bladder)
  • considered first-line, improve symptoms in around 70% of men
  • adverse effects: dizziness, postural hypotension, dry mouth, depression

5 alpha-reductase inhibitors e.g. finasteride

  • block the conversion of testosterone to dihydrotestosterone (DHT), which is known to induce BPH
  • unlike alpha-1 antagonists causes a reduction in prostate volume and hence may slow disease progression. This however takes time and symptoms may not improve for 6 months. They may also decrease PSA concentrations by up to 50%
  • adverse effects: erectile dysfunction, reduced libido, ejaculation problems, gynaecomastia