Alpha-1 blockers

Question 1

What is the mechanism of alpha-1-blockers in urinary outflow obstruction?

Answer 1

blocks alpha-1-adrenoreceptors in bladder neck and prostate (smooth muscle), improves urine flow.

Question 2

Why may you avoid prazosin in the elderly?

Answer 2

Elderly –> more susceptible to orthostatic hypotension.

ref AMH

Question 3

What are the side effects of Prazosin?

Answer 3

hypotension, orthostatic hypotension
dizziness (all less frequent with alfuzosin and tamsulosin);
nasal congestion
urinary urgency
headache
weakness, fatigue, drowsiness