CARDIO + RENAL/GU: ALPHA BLOCKERS

Question 1

ALPHA BLOCKERS: INDICATIONS

Answer 1

• 1st line in BPH

- Add on tx in RESISTANT HTN

Question 2

ALPHA BLOCKERS: MOA

Answer 2

Selective for A1 adrenorecptor
- Smooth muscle (blood vessels and urinary tract - bladder neck and prostate)
- Stimulation induces contraction; blockade induces relaxation
- Alpha blockers = vasodilatation and a fall in BP
REDUCED RESISTANCE TO BLADDER OUTFLOW

Question 3

ALPHA BLOCKERS: ADVERSE EFFECTS

Answer 3

• Postural HTN
• Dizziness
• Syncope (prominent after 1st dose - ACE INHIBITORS, ARBS)

Question 4

ALPHA BLOCKERS: WARNINGS

Answer 4

• Existing postural hypotension

Question 5

ALPHA BLOCKERS: INTERACTIONS

Answer 5

• Combining anti hypertensives results in additive BP lowering effects
• Avoid first dose hypotension, omit one dose or more of the existing HTN drugs on the day the alpha blocker is started
• Particularly the case for beta blockers which inhibit the reflex tachycardia that forms part of the compensatory response to vasodilatation

Question 6

ALPHA BLOCKERS: EXAMPLES

Answer 6

Doxazosin
Tamulosin
Alfuzosin