Cardiac drugs

Question 1

What’s the mechanism of action of loop diuretics?

Answer 1

Work on ATPase pump
Inhibit reabsorption of Na

Question 2

What are the SE of thiazides?

Answer 2

Hypokalaemia
Hyperglycaemia
Inc Urate levels- predispose to gout

Question 3

When is mannitol used?

Answer 3

Raised ICP
Rapidly shift fluid out of cells

Question 4

What’s the mechanism of Acetazolamide?

Answer 4

Affects glandular function
Reduces aqueous humor production
Drops anterior chamber pressure

Question 5

Where does Amiloride work?

Answer 5

Distal convoluted tubule

Question 6

How does Adenosine work?

Answer 6

Temporary complete HB at AV node
This breaks cycles caused by re-entrant arrhythmias/WPW
Diagnostically can assess underlying rhythm

Question 7

What are the SE of Amiodarone?

Answer 7

Photosensitivity
Eye problems
Thyroid disease
Pneumonitis

Question 8

Where does Digoxin work?

Answer 8

AV node

Question 9

What are the SE of Digoxin?

Answer 9

N&V
Yellow vision
Atrial arrhythmias
Conduction problems

Question 10

What are the indications of beta blockers?

Answer 10

SVT
AF
Migraine
Thyrotoxicosis
HTN

Question 11

Why should you not use beta blockers in SVT in WPW?

Answer 11

WPW pathway called Bundle of Kent next to AV node
SVT in WPW usually a circuit between these 2 areas
However WPW also more susceptible to AF
If beta blocker blocks AV node then rapid atrial transmission through accessory pathway reaches ventricle and can lead to a VF

Question 12

What drug can be used as prophylaxis in SVT?

Answer 12

Sotalol

Question 13

Which beta blockers are cardio selective?

Answer 13

Atenolol
Bisoprolol
Metoprolol

Question 14

Which beta blocker also works on alpha receptors?

Answer 14

Labetalol

Question 15

What are the SE of ACEi?

Answer 15

Renal impairment
Hyperkalaemia
HypoT
Cough
Anaphylactoid reactions

Question 16

What causes the cough with ACEi?

Answer 16

Build up of bradykinin

Question 17

What are the indications of nitrates?

Answer 17

Angina
Pulmonary oedema

Question 18

What is the mechanism of nitrates?

Answer 18

Act on venous vessels causing vasoD
Reduces preload

Question 19

How does Verapamil work?

Answer 19

Anti-arrhythmic drug
Slows AV conduction

Question 20

Who should Verapamil not be used with?

Answer 20

Impaired cardiac function
Negatively inotropic
Can predispose to cardiac failure

Question 21

Where does Nimodipine work?

Answer 21

Selective for cerebral vascular smooth muscle
Good for patients with SAH relaxing spasming vessels leading to ischaemia

Question 22

How does high & low dose adrenaline work?

Answer 22

Low dose acts on beta receptors
Causes systemic & pulmonary vasodilation
Inc HR & SV & contractility
High dose arts on alpha receptors
Intense systemic vasoC

Question 23

Why is adrenaline used in cold shock?

Answer 23

Low CO
High systemic vascular resistance
Reroute blood to areas with high use e.g brain & heart

Question 24

What is used in warm shock?

Answer 24

E.g Sepsis, spinal, anaphylaxis
Noradrenaline
Acts on alpha receptors to VasoC
Useful in shock not responding to fluid

Question 25

When is dopamine used?

Answer 25

Shock unresponsive to fluids in a cardiac cause
Acts on B1 receptors

Question 26

When is Dobutamine used?

Answer 26

Cardiogenic shock
Acts on B1 receptors
Reduces after load

Question 27

How do you decide which inotropes to use in a shocked patient?

Answer 27

1) Not responding to fluids
2) Dopamine = inc contractility
3) Warm shock = NorA. Cold shock = Adr

Question 28

When is Ephedrine & Metaraminol used?

Answer 28

Both Vasoconstriction
Ephedrine: Inc BP after spinal anaesthetic
Meta: Inc BP in general anaesthetic

Question 29

How does Atropine work?

Answer 29

Reduces vagal slowing

Question 30

How do statins work?

Answer 30

HMG CoA reductase inhibitors