40 - Drugs Affecting the Cardiovascular System

Question 1

Blood pressure considered chronically hypertensive

Answer 1

Over 140/90 mmHg

Question 2

Risk factors for hypertension

Answer 2

Smoking, diet, weight, stress

Question 3

Blood pressure considered hypertensive if diabetes or kidney disease is present

Answer 3

Over 130/80 mmhg

Question 4

Things that are initially altered to treat hypertension, before drug treatment is started

Answer 4

Altering diet, lowering stress, quitting smoking, losing weight

Question 5

Sensors of blood pressure

Answer 5

Baroreceptors, osmoreceptors

Question 6

What are the controlled variables in blood pressure regulation?

Answer 6

Heart rate
Stroke volume (HR x SV = CO)
Total peripheral resistance

Question 7

Effectors of blood pressure control

Answer 7

Heart, blood vessels, kidneys

Question 8

Effects of sympathetic tone (basal release of adrenaline/noradrenaline)
1)
2)
3)

Answer 8

1) Alpha1 adrenoceptors lead to increased vascular tone.
2) Beta1 adrenoceptors lead to increased heart rate, contractility
3) Beta1 adrenoceptors lead to decreased blood flow through kidney (less water excreted)

Question 9

Renal blood pressure regulation 
1)
2)
3)
4)
5)
6)

Answer 9

1) Decreased blood pressure detected by baroreceptors in pre-glomerular arteriole
2) Renin released
3) Renin converts angiotensinogen (released by liver) into angiotensin I.
4) Angiotensin-converting enzyme converts angiotensin I to angiotensin II
5) Angiotensin II leads to vasoconstriction, causes adrenal cortex to release aldosterone.
6) Aldosterone increases water reabsorption, decreases water excretion

Question 10

Antihypertensive drugs (ABCD)
1)
2)
3)
4)
5)

Answer 10

Angiotensin system inhibitors
Beta adrenoceptor antagonists
Calcium channel blockers
Diuretics
Other

Question 11

Effects of angiotensin II 
1)
2)
3)
4)

Answer 11

1) Via AT1 receptors, causes vasoconstriction
2) Via AT1 receptors, causes aldosterone to be released from adrenal cortex.
3) Responsible for remodelling in blood vessels, heart from chronically-high blood pressure
4) Mild enhancement of sympathetic nervous system (mild +’ve feedback loop)

Question 12

Action of angiotensin converting enzyme inhibitors

Answer 12

Block conversion of angiotensin I to angiotensin II.

Blocks degradation of bradykinin by ACE

Question 13

Effect of taking ACE inhibitors
1)
2)
3)

Answer 13

1) Reduce vascular tone
2) Reduce aldosterone production
3) Reduce cardiac hypertrophy
4) Block bradykinin degradation

Question 14

Alternative name for ACE

Answer 14

Kininase II (degrades bradykinin)

Question 15

When are ACE inhibitors and angiotensin receptor antagonists contraindicated?
1)
2)
3)

Answer 15

1) Pregnancy
2) Bilateral renal stenosis
3) Angioneurotic oedema

Question 16

Adverse events of ACE inhibitors 
1)
2)
3)
4)
5)
6)
7)

Answer 16

1) First-dose hypotension
2) Dry cough
3) Loss of taste
4) Hyperkalaemia
5) Acute renal failure
6) Itching, rash, angio-oedema
7) Foetal malformations

Question 17

Why can side effects of ACE inhibitors be itching, rash, angio-oedema?

Answer 17

Because an action of ACE is to break down bradykinin –> excess bradykinin if ACE is inhibited

Question 18

How can the hyperkalaemia associated with ACE inhibitors be treated?

Answer 18

Take a thiazide diuretic with ACE inhibitors

Question 19

Examples of ACE inhibitors 
1)
2)
3)
4)

Answer 19

1) - Captopril
2) - Enalapril
3) - Perindopril
4) - Ramipril

Question 20

Two types of drugs that interfere with angiotensin system

Answer 20

1) ACE inhibitors

2) Angiotensin receptor antagonists

Question 21

Suffix for angiotensin receptor antagonists

Answer 21

Sartan

Question 22

Clinically-useful angiotensin receptor to block

Answer 22

AT1, not AT2

Question 23

Effects of blocking AT1 receptor 
1)
2)
3)
4)

Answer 23

1) Reduce vasoconstriction
2) Reduce aldosterone
3) Reduce cardiac hypertrophy
4) Reduce sympathetic activity

Question 24

Side effects of angiotensin receptor antagonists
1)
2)
3)

Answer 24

1) Hyperkalaemia
2) Headaches
3) Dizziness

Question 25

How do ACE-inhibitors and angiotensin receptor antagonists compare in efficacy, side effects?

Answer 25

Comparabile in efficacy.
Have the same contraindications.
Angiotensin receptor antagonists have fewer side effects, as they don’t inhibit the degradation of bradykinin.

Question 26

Beta-adrenoceptor antagonists mechanism

Answer 26

Reduce cardiac output (rate, contractility)

Reduce renin release (blood volume, TPR)

Question 27

How do different beta-adrenoceptors differ?
1)
2)
3)

Answer 27

1) Beta1 and beta2 selectivity (newer are more beta1-selective)
2) Intrinsic sympathomimetic activity (now partial agonist activity)
3) Lipid solubility (to stop moving across blood brain barrier)

Question 28

Adverse events with beta-adrenoceptor agonists
1)
2)
3)
4)

Answer 28

1) Cold extremities
2) Fatigue
3) Vivd dreams, insomnia
4) Bronchoconstriction

Question 29

Why can beta blockers cause cold extremities?
1)
2)

Answer 29

1) Blockade of dilatory beta2 adrenoceptors in blood vessels
2) Reflex alpha1 adrenoceptor activity (responding to drop in blood pressure)
This limits blood to limbs

Question 30

Why can beta blockers cause fatigue?
1)
2)

Answer 30

1) Beta1 blockade reduces cardiac response

2) Beta2 blockade causes constriction of skeletal muscle blood vessels

Question 31

Why can beta blockers cause bronchoconstriction?

Answer 31

Beta2 adrenoceptors cause dilation of the airways.

Beta2 adrenoceptors can be blockaded by beta-blockers

Question 32

What are beta blockers contraindicated in?
1)
2)
3)

Answer 32

1) Asthma
2) Diabetes
3) Atrioventricular block

Question 33

Examples of non-selective beta blockers
1)
2)

Answer 33

1) Propranolol

2) Timolol

Question 34

Selective beta1 antagonists
1)
2)

Answer 34

1) Atenolol

2) Metoprolol

Question 35

Beta1 and beta2 partial agonist

Answer 35

Pindolol

Question 36

Ca2+ channel blocker mechanism

Answer 36

Inhibit voltage-gated L-type Ca2+ channels in myocardium and vasculature

Question 37

Effects of Ca2+ channel blockers
1)
2)

Answer 37

1) Reduce cardiac and vascular contractility

2) Reduce vascular resistance

Question 38

Example of Ca2+ blockers that reduces cardiac and vascular contractility

Answer 38

Verapamil (significant effects on cardiac and vascular muscle)

Question 39

Example of a Ca2+ channel blocker that is vascular selective

Answer 39

Dihydropyridines.

Reduce vascular resistance

Question 40

Adverse events associated with verapamil 
1)
2)
3)
4)

Answer 40

1) Oedema
2) Flushing
3) Headache
4) Bradycardia (careful if heart failure present)

Question 41

Adverse events associated with dihydropyridines 
1)
2)
3)
4)

Answer 41

1) Oedema
2) Flushing
3) Headache
4) Reflex tachycardia (careful if tachyarrhythmias present)

Question 42

Thiazide diuretic mechanism

Answer 42

Inhibit Na+/Cl- cotransporter in renal tube.
Leads to decreased Na+ and Cl- reabsorption in renal tube.
Increased Na+ and water loss from kidney.
K+ loss from collecting duct

Question 43

Thiazide diuretic effects

Answer 43

1) Increased water excretion from kidneys

2) Increased Na+, K+ excretion

Question 44

Side-effects of thiazide diuretics

Answer 44

1) K+ loss
2) Gout
3) Hyperglycaemia
4) Allergic reaction

Question 45

Example of a thiazide diuretic

Answer 45

Hydrochlorothiazide

Question 46

Why aren’t alpha1 adrenoceptor agonists used so much anymore?

Answer 46

Particularly elderly patients prone to fainting.
Can’t increase TPV when going from sitting to standing to increase blood pressure, so faint.

Reflex tachycardia