Renin-angiotension-aldosterone system

Question 1

What is the renin-angiotension-aldosterone system?

Answer 1

= major regulatory system within the body involved in homeostasis

Regulates:

• BP.
• Fluid volume
• Electrolyte levels (sodium and potassium)

Question 2

Components of the renin-angiotension-aldoestrone system?

Answer 2

Antiogensiongen.

Renin

Angiotensin I

Angiotensin converting enzyme (ACE)

Angiotensin II

Aldoestone

Angiotensin III and IV

Question 3

How does Angiotensin II increase BP?

Answer 3

• produces vasoconstriction and an increase in peripheral vascular resistance
• causes release of aldosterone from adrenal cortex which acts on kidney to conserve water and sodium
  = over all increases BP

How?
- Acts on 2 different types of G-protein coupled receptors
- Angiotensin II type 1 receptors (At1 receptors)
Angiotensin II Type 2 receptors (AT2)

Question 4

What is Bradykinin

Answer 4

= peptide produced by the action of enzyme kalikreom on kininogen

• produces vasodilation and a drop in peripheral vascular resistance
• increases vascular permeability
• involved in pain and inflammation

Question 5

What are the medications which modify the Angiotensin-aldosterone system?

Answer 5

1. ACE inhibitors (prils)
2. Angiotensin II antagonists (startans)
3. Renin Inhibitors (not in Aus)

Question 6

What is the MOA of ACE inhibitors, with example?

Answer 6

= Block conversion of angiotensin 1 to angiotensin 2

• inhibits breakdown of bradykinin
• reduce angiotensin II levels

e.gt. ramipril and perindopril

Question 7

Adverse reaction of ACE inhibitors?

Answer 7

• hypotension, headache,
• hyperkalaemia
• renal impairment
• persistant non-producing cough
• hepatitis
• pancreatitis
• Angioedema

Question 8

Interactions with Ace inhibitors?

Answer 8

• potassium sparing diuretics

Question 9

Nursing practice points for ACE inhibitors?

Answer 9

WHen starting ACE inhibitors:

• stop potassium supplements and potassium sparing diuretics
• start with low dose
• review use of NSAIDS

Check renal function and electrolytes before starting on ACE inhibitors

Question 10

Indications for ACE inhibitors?

Answer 10

• Hypertension
• Angina
• Renin-angiotension aldosterone system
• heart failure

Question 11

MOA of Angiotension II receptor agatonists (startans)?

Answer 11

= act as competitive antagonists of a II and a I type I receptors

(block action of angiotensin II at receptors)

Question 12

Indications for Startans?

Answer 12

• hypertension
• heart failure
• renin-angiotension aldosterone system
• renal disease

Question 13

Adverse reactions of Startans?

Answer 13

• dizziness, headache
• hyperkalaemia
• Sprune-like enteropathy
• abnormal liver function

Question 14

Interactions of startans

Answer 14

• OTC cold and flu products may increase BP
• NSAIDS
• Tripple whammy

Question 15

Nursing practice points for Startans?

Answer 15

When starting

• stop potassium supplements and potassium sparing diuretics
• start with low dose
• review use of NSAIDS

Check renal function and electrolytes before starting on ACE inhibitors