CV Meds - Alpha Blockers

Question 1

name 3 alpha blockers

Answer 1

Doxazosin
Tamsulosin
Alfuzosin

Question 2

give the 2 indications

Answer 2

1. first line to improve lower urinary tract symptoms in bening prostatic enlargement when lifestyle changes are insufficient
2. add-on treatments in resistant hypertension when CCB, ACEi, ARB insufficient

Question 3

what subtype of alpha receptor do they mind to?
where in the body are they found?
what does inhibition of these receptors cause?

Answer 3

• alpha 1 adrenoreceptor
• smooth muscle including blood vessels in urinary tract
• inhibition causes vasodilation and a fall in blood pressure and reduces resistance to urine outflow from the bladder

Question 4

what are the main adverse effects and when should they be cautioned?

Answer 4

postural hypotension, dizziness, syncope
avoid in people with existing postural hypotension

Question 5

what could you do to avoid first-dose hypotension if the patient already takes antihypertensives?

Answer 5

omit doses of one or more existing antihypertensives on the day the alpha blocker is started
Especially for B-blockers - inhibit the refelx tachycardia that forms part of the compensatory response to vasodilation

Question 6

what can taking alpha blockers with phosphodiesterases type 5 (PDE-5) inhibitor lead to?
give eg of a PDE-5 inhibitor?
is this likely to be a common combination?

Answer 6

symptomatic hypotension
sildenafil
yes - men with benign prostatic enlargement may also suffer with erectile dysfunction - alpha blocker treatment should be stabilised before starting PDE-5 inhibitor

Question 7

True or False - doxazosin, alfuzosin and tamsulosin are licensed for benign prostatic enlargement and hypertension

Answer 7

False - only doxazosin is licensed for hypertension as well as benign prostatic hypertension

Question 8

alpha blockers are reserved for resistant hypertension - when might you start someone on these at an early stage?

Answer 8

if they have benign prostatic enlargement - treat 2 conditions with one drug