Drugs for heart failure

Question 1

What is heart failure?

Answer 1

a chronic failure of the heart to provide sufficient output to meet the body’s requirements

Question 2

In very broad terms, what do heart failure drugs do?

Answer 2

reduce the work load oof the heart

Question 3

What class of drugs do cardiac glycosides and β-adrenergic agonists fall under?

Answer 3

positive inotropes

Question 4

Explain how cardiac glycosides work

Answer 4

They block the Na+/K+ ATPase pump
leads to an increased intracellular Na+ level
this leads to decreased action of the Na+-Ca2+ exchanger
So less Ca2+ is taken out of the cell–>increased Ca2+ levels in the cell
So more Ca2+ stored in the SER
so increased force of contraction

Question 5

As well as increasing inotropy of the heart, what do cardiac glycosides also do?

Answer 5

Increase vagal nerve activity

so slow the AV conduction and the heart rate

Question 6

What do β adrenoceptor agonists cause?

Answer 6

increased inotropy

Question 7

Give an example of a β adrenoreceptor agonist

Answer 7

dobutamine

Question 8

two occasions when you would use a β adrenoceptor agonist?

Answer 8

cardiogenic shock

acute but reversible heart failure

Question 9

How do ACE inhibitors work and what effet do they have?

Answer 9

ACE inhibitors inhibit the conversion of Angiotensin 1 to angiotensin 2
So causes vasodilation, decreased water retention etc..
So overall reduced the TPR and afterload

Question 10

3 types of drugs used to treat angina?

Answer 10

β adrenoceptor blockers
Ca2+ channel antagonists
Organic nitrates

Question 11

Explain the effect of organic nitrates

Answer 11

NO is a Powerful vasodilator

Note NO is the product when the drug has been completely broken down in the vasculature

Question 12

Explain how NO causes vasodilation

Answer 12

NO activates Guanylate cyclase
increases cGMP
overall lowers intracellular Ca2+ levels–>relaxation

Question 13

Which vessels do organic nitrates preferentially cause dilation?

Answer 13

veins

Question 14

How does this venodilation help to alleviate the symptoms of angina?

Answer 14

venodilation–>reduced preload–>reduced work load of the heart so heart filling less so not pumping as hard–>decreased oxygen demand

Question 15

What other way do organic nitrates work to alleviare the symptoms?

Answer 15

vasodilate the collateral circulation of the coronary arterie–>increased blood flow to the area of ischaemia

Question 16

Name three heart conditions that carry increased risk of thrombus formation

Answer 16

atrial fibrillation
Acute MI
Mechanical prosthetic valves

Question 17

Two types of antithrombotic drugs?

Answer 17

anticoagulants

Antiplatelet drugs

Question 18

Two examples of anticoagulent drugs?

Answer 18

Heparin: Inhibits thrombin
Warfarin: Antagonises action of vit K

Question 19

an example of antiplatelet drug?

Answer 19

Aspirin

Question 20

five types of drugs to treat hypertension?

Answer 20

ACE inhibitors
Ca2+ channel blockers
Diuretics
β-blockers
alpha 1 adrenoceptor antagonists