Renal and urology

Question 1

What are the mechanisms and potential side effects of both alpha 1 agonists and 5a reductase inhibitors?

Answer 1

Alpha-1 antagonists e.g. tamsulosin, alfuzosin
-Decrease smooth muscle tone (prostate and bladder)
considered first-line, improve symptoms in around 70% of men
-SE –> 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%
• SE –> erectile dysfunction, reduced libido, ejaculation problems, gynaecomastia