LEC - 7.1 - ACEs & ARBs

Question 1

explain the RAAS System

Answer 1

Renin Angiotensin Aldosterone System
A system that kicks into place during hypotension
This involves the kidneys, liver, lungs, and heart
Hypotension activates prorenin which is converted to renin
Renin is turned into angiotensin in the liver
Angiotension becomes angiotensin I in the lungs
Angiotension I is introduced to angiotensin converting enzyme (ACE) to become angiotensin II
Angiotensin II - a powerful vasoconstrictor, to help address hypotension
Angiotensin II travels to the adrenal cortex and is converted to Aldosterone
Aldosterone - increases water reabsorption, meaning decreased urine output and increased blood pressure

Question 2

A system that kicks into place during hypotension

Answer 2

Renin Angiotensin Aldosterone System

Question 3

The RAAS involves which organs?

Answer 3

the kidneys, liver, lungs, and heart

Question 4

___ activates prorenin which is converted to renin

Answer 4

Hypotension

Question 5

Hypotension activates ___ which is converted to renin

Answer 5

prorenin

Question 6

Renin is turned into ___ in the ___

Answer 6

angiotensin

liver

Question 7

Angiotension becomes angiotensin I in the ___

Answer 7

lungs

Question 8

Angiotension I is introduced to ___ to become angiotensin II

Answer 8

angiotensin converting enzyme (ACE)

Question 9

this is a powerful vasoconstrictor, to help address hypotension

Answer 9

Angiotensin II

Question 10

Angiotensin II travels to the ___ and is converted to ___

Answer 10

adrenal cortex

Aldosterone

Question 11

this increases water reabsorption, meaning decreased urine output and increased blood pressure

Answer 11

Aldosterone

Question 12

one of the body’s homeostatic mechanisms that helps to maintain blood pressure at nearly constant levels, it provides a rapid negative feedback loop in which an elevated blood pressure causes the heart rate to decrease

Answer 12

Baroreflex

Question 13

130/90 BP = ?

Answer 13

Prehypertension

Question 14

? BP = Prehypertension

Answer 14

130/90 BP

Question 15

> 140/>90 BP = ?

Answer 15

Hypertension

Question 16

? BP = Hypertension

Answer 16

> 140/>90 BP

Question 17

Types of hypertension:

Answer 17

Essential

Secondary

Question 18

Hypertension of unknown origin.

Answer 18

Essential Hypertension

Question 19

Hypertension that results from other disease process

Answer 19

Secondary Hypertension

Question 20

Environmental Factors that Cause Hypertension:

Answer 20

Stress

Increased sodium intake

Obesity

Smoking

Question 21

This antihypertensive medication prevents ACE from converting angiotensin I to angiotensin II, a powerful vasoconstrictor and stimulator of aldosterone release. This action leads to a decrease in blood pressure and in aldosterone secretion, with a resultant slight increase in serum potassium and a loss of serum sodium and fluid.

Answer 21

ACE Inhibitor

Question 22

Examples of ACE Inhibitors:

Answer 22

captopril (Capoten)

lisinopril (Zestril)

enalapril (Vasotec)

ramipril (Altace)

fosinopril (Monopril)

Question 23

Pharmacokinetics:
Available only orally
70% - 75% is absorbed
Partly absorbed and partly excreted unchanged in urine
Food interferes with its absorption
Half life: 2 hours, but action stays for 6-12 hours

Answer 23

Captopril

Question 24

Pharmacokinetics of Captopril:
Administration:
Absorption:
Excretion:
Teachings:
Half life:

Answer 24

Available only orally

70% - 75% is absorbed

Partly absorbed and partly excreted unchanged in urine

Food interferes with its absorption

2 hours, but action stays for 6-12 hours

Question 25

Adverse Effects of Captopril

Answer 25

Cough – persistent brassy cough Hyperkalemia in renal failure patients with K+ sparing diuretics, NSAID and beta blockers Hypotension – sharp fall may occur with the 1st dose Acute renal failure Angioedema: swelling of lips, mouth, nose, etc. Rashes, urticaria Dysgeusia: loss or alteration of taste

Question 26

term for the swelling of lips, mouth, nose, etc.

Answer 26

Angioedema

Question 27

term for the loss or alteration of taste

Answer 27

Dysgeusia

Question 28

Contraindications for Captopril

Answer 28

Pregnancy bilateral renal artery stenosis hypersensitivity and hyperkalemia

Question 29

Advantages over captopril: Longer half life and requires a 5-20 mg once daily dosage regimen Absorption not affected by food Rash and loss of taste are less frequent Longer onset of action Less side effects

Answer 29

Enalapril

Question 30

Pharmacokinetics of Enalapril: Administration: Absorption: Excretion: Teachings: Half life:

Answer 30

Longer onset of action Absorption not affected by food Rash and loss of taste are less frequent Longer onset of action Longer half life and requires a 5-20 mg once daily dosage regimen

Question 31

No postural hypotension or electrolyte imbalance (no fatigue or weakness) Safe in asthmatics and diabetics Prevention of secondary hyperaldosteronism and K+ loss Renal perfusion is well maintained No hyperuraecemia or deleterious effect on plasma lipid profile No rebound hypertension Minimal worsening of quality of life – general wellbeing, sleep and work performance

Answer 31

1st line of Drug

Question 32

Nursing Implementation for 1st line Drugs

Answer 32

Encourage patient to implement lifestyle changes Monitor for hypotension Let client rest in supine position beginning one hour after administration and for 3-4 hours after the first dose Observe for hypersensitivity reaction, particularly angioedema Monitor for neutropenia and signs of infection Monitor for persistent dry cough or changes in cough pattern Monitor for hyperkalemia Monitor for liver and kidney function

Question 33

These antihypertensive drugs selectively bind the angiotensin II receptors sites in vascular smooth muscle and in the adrenal gland to block vasoconstriction and the adrenal cortex release of aldosterone These actions block the blood pressure – raising effects of the renin angiotensin system and lower blood pressure.

Answer 33

Angiotensin II Receptor Blockers (ARBs)

Question 34

Examples of ARBs:

Answer 34

Candesartan ( Blopress) Losartan ( Combizar) Irbesartan (Aprovel) Valsartan (Diovan)

Question 35

Pharmacokinetics of ARBs:

Answer 35

Absorption not affected by food but unlike ACE Inhibitor its bioavailability is low High first pass metabolism

Question 36

Adverse effects of ARBs:

Answer 36

Foetopathic like ACE Inhibitors – not to be administered in pregnancy Rare 1st dose effect of hypotension Low dysgeusia and dry cough Lower incidence of angioedema

Question 37

Theoretical superiority of ARBs over ACEIs:

Answer 37

Cough is rare – no interference with bradykinin and other ACE substrates Heart rate remains unchanged and CVS reflexes are not interfered No significant effect in plasma lipid profile, insulin sensitivity and carbohydrate tolerance Mild uricosuric effect