Theme 3: Lecture 14 - Drug treatments for CVD 4 (ischaemic heart disease)

Question 1

What type of prevention is treatment to reduce hypercholesterolaemia in ischaemic heart disease

Answer 1

secondary prevention

Question 2

What are the 2 main sources of cholesterol

Answer 2

• Diet

- Made in liver

Question 3

What is the frontline treatment for hypercholesterolaemia

Answer 3

Statins

Question 4

Name a statin

Answer 4

Simvastatin

Question 5

How do statins work

Answer 5

• Statins decrease the production of cholesterol in the liver by inhibiting the HMG CoA enzyme.
• This stimulates the liver cells to express LDL receptors and allows the liver cells to scavenge LDL cholesterol from the plasma.
• This reduces plasma LDL cholesterol levels.

Question 6

What are drugs used to treat hypercholesterolaemia designed to do

Answer 6

Either inhibit cholesterol uptake from the GI tract or reduce production in the liver

Question 7

Name 2 antiplatelet agents

Answer 7

• Aspirin

- Clopidogrel

Question 8

Name an ACE inhibitor

Answer 8

Ramipril

Question 9

Name an ARB

Answer 9

Losartan

Question 10

How do ACE inhibitors and ARBs help in secondary prevention of ischaemic heart disease

Answer 10

They decrease workload on the heart

Question 11

What is the drug treatment for unstable angina

Answer 11

• As for stable angina and with an antiplatelet agent

- The antiplatelet agent could be aspirin or aspirin and clopidogrel (prasugrel, tricagrelor)

Question 12

Why are patients with unstable angina also given an antiplatelet agent

Answer 12

• The plaques are unstable

- More likely to rupture and form a thrombus

Question 13

Describe what platelet activation does

Answer 13

• Platelet activation occurs when the endothelial cells become damaged.
• This releases ADP which acts on P2Y12 receptors to stimulate the platelet to express GPIIb/IIIa receptors.
• Fibrinogen binds to these receptors to cross link different platelets.
• Activation also causes activation of COX which also helps platelet activation through the production of Thromboxane A2.

Question 14

How does aspirin act as an anti platelet agent

Answer 14

It inhibits cyclo-oxygenase enzyme irreversibly

Question 15

How does clopidogrel work as an anti platelet drug

Answer 15

It is an ADP antagonist and blocks P2Y12 receptors

Question 16

What is a prodrug

Answer 16

A drug that after administration is metabolised in the body into the pharmacologically active drug

Question 17

How clopidogrel converted from the inactive into the active drug in the body

Answer 17

• Clopidogrel is absorbed in the gut

- Travels to the liver and undergoes CYP2C19 dependent oxidation to be transformed into the active drug

Question 18

Drug treatment for an MI

Answer 18

• Pain Relief: (Diamorphine mu-opioid receptors - Decreases pain, anxiety, sympathetic drive, vasodilates)
• Oxygen
• Aspirin
• GTN
• Clot busting drugs

Question 19

How do ACE inhibitors help to treat MI

Answer 19

• Decrease cardiac workload

- prevents remodelling development of heart failure

Question 20

How do beta blockers help to treat MI

Answer 20

• Decrease cardiac workload

- prevents arrhythmias

Question 21

How do anticoagulants help to treat MI

Answer 21

In case of long term bed rest, prevents thrombus formation

Question 22

Name 5 anticoagulants

Answer 22

• warfarin
• apixaban
• rivaroxaban
• dabigatran
• LMWH (e.g.tinzaparin)

Question 23

What is digoxin used to treat

Answer 23

Heart failure

Question 24

How does digoxin work

Answer 24

• Digoxin binds to the Na+/K+ ATPase and inhibits its action.
• This will increase levels of Na+ ions inside the heart muscle cells.
• This increase will in turn inhibit the Na+/Ca2+ exchanger which will lead to a build up of Ca2+ inside the muscle cell and a stronger contraction

Question 25

What is amiodarone used to treat

Answer 25

Dysrhythmias

Question 26

How does amiodarone work

Answer 26

K+ channel blocker that increases the refractory period of ventricular myocytes and can terminate arrhythmias