Lecture 3: Targets of RAAS

Question 1

What are the drug targets of RAAS?

Answer 1

ACE inhibition
ARBs
Aldosterone antagonists
Ca channel blockers
Diuretics
Beta blockers

Question 2

Whats an example of an ACE inhibitor?

Answer 2

Cilazipril = decreased ANG2 levels

Question 3

What is the dual action of ACE inhibitors?

Answer 3

ACE = kininase 2 and is also resposible for degrading bradykinin..

Can result in

1. Dry cough
2. Angioeodema

(Bradykinin causes vasodilation, increase vascular permeability and sensitises pain nerves)

Question 4

Where does ACE inhibition angioedema typically occur? whats the solution?

Answer 4

• Most commonly affecting lips, larynx, and pharynx

Cease medication, supportive care, bradykinin specific treatment

Question 5

Whats an example of ARBs?

Answer 5

• Competitive antagonists at AT1 receptors

i. e Losartan

Question 6

ACE-I, ARBs or both?

Answer 6

ACE-Is and ARBs reduce likelihood of CV event

ACE-Is generally more effective, but more likely to display adverse effects

ARBs possible as substitute

Combo can be dangerous

Question 7

Whats an example of an aldosterone antagonist? and what does it do?

Answer 7

Spironolactone

• Antagonist at MC receptor
• Inhibits Na reabsoprtion caused by aldosterone

Question 8

What are Ca channel blockers, what do they do?

Answer 8

Block SM contraction

• > Decreased vasoconstriction
• > Decreased BP

i.e Verapamil, Nifedipine

Question 9

What are diuretics and what do they do?

Answer 9

Diuretics appose ANG2 retention of Na and water

• > Primarily serve to increase Na excretion
• > Variety of targets within renal tubules
• > i.e Amiloride particularly relevant in counteracting RAAS

Question 10

Write some notes on beta blockers:

Answer 10

• Main action is on SNS, but this interacts with RAAS
• Competitive antagonists at beta adrenergic receptors esp. B1
• Decreases cardiac contractility, decrease renin secretion

i.e atenolol