Pharmacological treatment of Angina

Question 1

what drugs are given to reduce chest pain symptoms?

Answer 1

-beta blockers, nitrates, calcium channel antagonists, nirocandil, ivabradine, ranolazine

Question 2

what 4 drugs are given to prolong survival?

Answer 2

beta blockers, aspirin, statins , ACE

Question 3

what 3 factors shorten the window for coronary flow?

Answer 3

• shorten diastole increase HR
• increased ventricular end diastolic pressure aortic stenosis
• reduced diastolic arterial pressure mitral or aortic valve incompetence

Question 4

what is the common cause of coronary ischaemia?

Answer 4

atherosclerosis causing a lack of blood flow to areas which require it

Question 5

what is ischaemia?

Answer 5

ischemia is a restriction of blood supply to tissues causing shortage of glucose and oxygen needed for cellular metabolism

Question 6

what is angina? what feelings are experienced as a result?

Answer 6

chest pain due to inadequate supply of oxygen to the heart

• crushing or severe pain
• feeling of suffocation and pressure behind the sternum

Question 7

what is the usual distribution of pain from angina?

Answer 7

chest, arm, neck and jaw

Question 8

what factors bring on pain due to angina?

Answer 8

exertion, cold, excitement

Question 9

what are the 3 different categories of angina?

Answer 9

• Printzmetals variant angina
• chronic stable angina
• unstable angina

Question 10

what is the difference between supply and demand ischaemia?

Answer 10

supply- even at rest you can’t get a supply of blood to that area
demand- exercise stresses the heart muscle then demand for oxygen goes up to area of the heart and the heart can’t meet the demand

Question 11

describe the features of stable angina. what is the principle of treating stable?

Answer 11

• predictable chest pain on exertion
• fixed narrowing of coronary arteries

-treat by decreasing workload of heart so as to decrease O2 demand, prolong survival

Question 12

describe the features of unstable angina. what is it usually associated with?

Answer 12

• occurs at rest with less exertion than stable angina

- associated with thrombus from ruptured plaque

Question 13

what is the cause of Printzmetals variant angina?

Answer 13

-caused by coronary artery spasm

Question 14

what are the 2 broad classes of drugs used to treat angina? what are their objectives?

Answer 14

• work by reducing the metabolic demand of the muscle
• vasodilators- decrease preload and afterload
• beta blockers-slow down the heart

Question 15

what is the mechanism of action of vasodilators?

Answer 15

• decrease preload decreasing volume of blood returning to the heart, heart heart doesn’t need to cope with pumping high volume of blood
• afterload decreased means pressure heart is working against is less therefore less demand on heart

Question 16

what is the mechanism of action of beta blockers?

Answer 16

act on beta 1 receptors which are intrinsically related with rate of the heart
decrease cardiac oxygen consumption by slowing the rate of the heart

Question 17

what are 2 examples of beta blockers?

Answer 17

• bisoprolol

- atenolol

Question 18

what class of drug are calcium antagonists?

Answer 18

vasodilators

Question 19

what is the mechanism of action of calcium antagonists on smooth muscle?

Answer 19

calcium regulates activity of smooth muscle constriction, constriction of the vasculature. hence decreasing constriction of smooth muscle decreases total peripheral resistance
=drop in afterload and dilates coronary vessels

Question 20

how can calcium antagonists also affect the rate of the heart?

Answer 20

• calcium channels present in conduction pathways of the heart
• calcium influx drives action potential generated in nodal tissue of heart
• hence altering influx of calcium in nodal tissue means you can control heart rate
• prevent opening of L-type DHP calcium channels

Question 21

what are examples of DHP derivative calcium antagonists? what do they affect?

Answer 21

amlodipine, lercanidipine

-these affect vasculature only

Question 22

give examples of rate limiting calcium antagonists. What do they affect?

Answer 22

verapamil,diltiazem

-affect both heart rate and afterload

Question 23

what are the side affects of calcium antagonists?

Answer 23

headache, constipation, ankle oedema because of increased dilation of vessels q

Question 24

what type of angina is treated with DHP derivative calcium antagonists?

Answer 24

printzmetals variant angina

Question 25

what class of drugs are organic nitrates?

Answer 25

powerful vasodilators

Question 26

when are organic nitrates taken?

Answer 26

prior to exertion and at early onset of angina

Question 27

what is the mechanism of action of organic nitrates?

Answer 27

• metabolised to nitric oxide

- relax smooth muscle by diffusing across the short distances between endothelial cells and smooth muscle

Question 28

how do nitrates help treat angina?

Answer 28

• decreases preload, predominately absorbed in the venous system
• decreases cardiac workload by causing dilation of collateral coronary vessels this allows alternative routes for blood to get to ischaemic vessels

Question 29

what are 2 examples of organic nitrates?

Answer 29

• glyceryl trinitrate

- isosorbide mononitrate

Question 30

what types of angina can organic nitrates be used to treat?

Answer 30

stable angina- glyceryl trinitrate shortly before exercise

unstable angina- IV glyceryl trinitrate

Question 31

what are the side effects of organic nitrates?

Answer 31

• headaches

- postural hypotension due to altering the dilation of veins

Question 32

what is the mechanism of action of potassium channel activators?

Answer 32

• have a nitric oxide dilating effect+ decrease preload
• activates potassium ATP channels hyperpolarises vascular smooth muscle means smooth muscle less likely to depolarise increasing dilation and decreasing total peripheral resistance

Question 33

what is an example of potassium channel activator?

Answer 33

Nicorandil

Question 34

what are side effects of potassium channel activators?

Answer 34

• headaches
• dizziness
• flushing

Question 35

how does Ivabradine operate?

Answer 35

inhibits f-type channels in the heart decreasing the slope of the pacemaker potential causing a decrease in heart rate