Pharmacological Treatment of Angina

Question 1

What shrinks the window for coronary blood flow?

Answer 1

• shortening diastole (increasing HR)
• increased ventricular end diastolic pressure (aortic valve stenosis)
• reduced diastolic arterial pressure (eg. mitral/aortic valve incompetence or heart failure)

Question 2

What are some causes of ischaemia?

Answer 2

• coronary ischaemia usually caused by atherosclerosis and cause angina
• sudden ischaemia usually caused by thrombosis and can cause MI

Question 3

What are some causes of angina?

Answer 3

• coronary ischaemia

- coronary spasm (pathological vasomotion)

Question 4

What is the result of prolonged ischaemia?

Answer 4

• cellular calcium overload

- can cause cell death and dysrhythmias

Question 5

What causes the chest pain associated with angina pectoris?

Answer 5

inadequate oxygen supply to the heart

Question 6

What is the character of the chest pain associated with angina?

Answer 6

• severe and crushing
• tight, constricting
• dull, heavy

Question 7

Describe the distribution of pain associated with angina

Answer 7

• retrosternal/left side of chest
• can radiate to left arm/neck/jaw/back
• brought on by exertion/change in state (hot/cold)

Question 8

What is thought as the cause of the angina pain?

Answer 8

• chemical factors that cause pain in skeletal muscle

- K+, H+, adenosine

Question 9

What are the classes of angina and their type of ischaemia?

Answer 9

• stable angina: demand ischaemia
• unstable angina: supply ischaemia
• variant (Prinzmetal) angina: supply ischaemia

Question 10

Stable angina

Answer 10

• fixed narrowing of coronary arteries
• predictable chest pain on exertion
• caused by a stressor

Question 11

Unstable angina

Answer 11

• occurs at rest with less exertion than stable angina
• associated with thrombus around a ruptured atheromatous plaque
• incomplete occlusion of vessel

Question 12

Variant (Prinzmetal) angina

Answer 12

• uncommon
• caused by coronary artery spasm
• sometimes associated with atherosclerosis

Question 13

Drugs that reduce chest pain symptoms

Answer 13

• doesn’t treat underlying cause
• B-blockers
• nitrates
• Ca+ channel antagonists
• nirocandil
• ivabradine
• ranolazine

Question 14

Drugs that prolong survival with angina

Answer 14

• B-blockers
• aspirin
• statins
• angiotensin converting enzyme inhibitors
• angiotensin II receptor blockers

Question 15

What are the main lines of treatment of angina?

Answer 15

• short-acting nitrates for preventing/treating episodes of angina
• B-blocker given first
• if not CCB used
• can be given together
• if not/contraindications, nicorandil and ivabradine can be considered

Question 16

Vasodilator antianginal drugs

Answer 16

• organic nitrates
• nicorandil
• calcium antagonists
• decrease preload/afterload
• decreases metabolic demand of muscle

Question 17

HR lowering antianginal drugs

Answer 17

• B-blockers
• ivabradine
• prevents huge elevation in HR opening coronary window
• decreases metabolic demand of muscle

Question 18

What drugs are organic nitrates?

Answer 18

• glyceryl trinitrate

- isosorbide mononitrate

Question 19

How do organic nitrates work in treatment of angina?

Answer 19

• powerful vasodilators
• metabolise to NO to relax smooth muscle
• act on veins to decrease preload
• high concentrations increase afterload
• dilate collateral coronary vessels
• improves blood flow to regions of myocardium with restricted blood flow to restore perfusion more equally
• variant angina

Question 20

Clinical applications of organic nitrates in angina

Answer 20

• stable angina: sublingual glyceryl trinitrate shortly before exertion/isosorbide mononitrate long before
• unstable angina/acute heart failure: IV glyeryl trinitrate
• chronic heart failure: isosorbide mononitrate with hydralazine in patients of african american origin esp

Question 21

What are the side effects of organic nitrates?

Answer 21

• headache

- postural hypotension

Question 22

Common B-blockers used in the treatment of angina

Answer 22

• bisoprolol

- atenolol

Question 23

Explain the mechanism of action of B-blockers

Answer 23

• decreases cardiac oxygen consumption by slowing down HR

- increases period of diastole to allow perfusion of coronary arteries

Question 24

Explain the mechanism of action of CCBs

Answer 24

• prevent opening of voltage-gated L-type Ca channels
• prevents Ca2+ entry
• stops constriction of smooth muscle
• vasodilator effect on resistance vessels and coronary vessels
• decreases afterload

Question 25

What are the 2 types of CCBs and examples of these?

Answer 25

• DHP derivatives eg. amlodipine and lercanidipine

- rate-limiting: verapamil and diltiazem

Question 26

Additional effects of veramipil and diltaziem

Answer 26

• reduce and impair AV conduction and myocardial contractility

Question 27

When is amlodipine and lercanidipine used in angina patients?

Answer 27

• patients with heart failure
• used instead of b-blocker in prinzmetal angina
• can be used in addition to b-blockers in stable/unstable angina

Question 28

When is diltiazem and verapamil not used in angina patients?

Answer 28

• heart failure
• bradycardia
• AV block
• b-blocker
• as it slows down heart

Question 29

What are the side effects of CCBs?

Answer 29

• headache
• constipation
• ankle oedema

Question 30

Treatment for antidysrhythmias/AF?

Answer 30

verapamil

Question 31

Treatment for hypertension?

Answer 31

• amlodipine

- lercanidpine

Question 32

What drug falls under potassium channel activators?

Answer 32

Nicorandil

Question 33

Explain the mechanism of action of nicrorandil

Answer 33

• combines activation of K+ATP channels with nitrovasodilator actions
• hyperpolarisation of vascular smooth muscles
• arterial and venous dilator
• headaches, flushing, dizziness
• used in patients with symptoms even with other drugs

Question 34

Mechanism of action of Ivabradine

Answer 34

• inhibits f-type channels in heart
• reduces cardiac pacemaker activity
• inhibits HR

Question 35

When is ranolazine used?

Answer 35

as a last resort for angina