Anti-Arrhythmia Drugs

Question 1

How is adenosine administered?

Answer 1

IV bolus

Question 2

What is dispoyramide used for?

Answer 2

prevent recurrent ventricular arrhythmias

Question 3

What is the mechanism of action of class IB drugs?

Answer 3

rapid association and dissociation rate - prevent premature beats

Question 4

What is the adverse side effect of flecainide?

Answer 4

may trigger ventricular arrhythmias

Question 5

What is the mechanism of action of class IC drugs?

Answer 5

slow association and dissociation rate - depress conduction

Question 6

What class is verapamil?

Answer 6

class IV

Question 7

What is the cycle of sodium channels?

Answer 7

non-conducting resting state - depolarisation - conducting open state - maintained depolarisation - non-conducting inactivated state - repolarisation - resting state

Question 8

What is the mechanism of action of adenosine?

Answer 8

activates alpha 1 adrenoceptors coupled to Gi/o - opens ACh sensitive K+/GIRK channels - hyperpolarises AV node - supresses impulse conduction

Question 9

What is the mechanism of action of class III drugs?

Answer 9

target potassium channels - prolong AP duration - increase refractory period

Question 10

How is dispoyramide administered?

Answer 10

oral

Question 11

What is paroxysmal supraventricular tachycardia?

Answer 11

atrial firing rate of 140-250 bpm, caused by re-entry

Question 12

How is procainamide administered?

Answer 12

IV

Question 13

What class are propranolol and atenolol?

Answer 13

class II

Question 14

What might a high dose of verapamil cause?

Answer 14

heart block

Question 15

What is adenosine used for?

Answer 15

terminate paroxysmal supraventricular tachycardia, acute atrial fibrillation and atrial flutter

Question 16

What is verapamil used for?

Answer 16

prophylaxis of atrial flutter and atrial fibrillation

Question 17

How is lignocaine administered?

Answer 17

IV

Question 18

What is the mechanism of action of class IV drugs?

Answer 18

target calcium channels - slow conduction in SA and AV nodes - decreased force of cardiac contraction

Question 19

What is digoxin used for?

Answer 19

atrial fibrillation

Question 20

What is lignocaine used for?

Answer 20

ventricular arrhythmias following MI

Question 21

What is the mechanism of action of amiodarone?

Answer 21

supresses re-entry

Question 22

What is procainamide used for?

Answer 22

ventricular arrhythmias post MI

Question 23

What is the mechanism of action of class I drugs?

Answer 23

block open and inactivated sodium channels - dissociate in diastole

Question 24

What are the side effects of long term use of amiodarone?

Answer 24

pulmonary fibrosis, thyroid disorders, photosensitivity reactions, peripheral neuropathy

Question 25

What class IB drug only blocks inactivated sodium channels?

Answer 25

lignocaine

Question 26

What are propranolol and atenolol used for?

Answer 26

control supraventricular tachycardia

Question 27

What is the mechanism of action of class IA drugs?

Answer 27

moderate association and dissociation rate - slow rise of AP - prolong refractory period

Question 28

How is digoxin administered?

Answer 28

IV infusion or oral

Question 29

What class is lignocaine?

Answer 29

IB

Question 30

What is the mechanism of action of propranolol and atenolol?

Answer 30

supress excess sympathetic drive that may trigger ventricular tachycardia

Question 31

Why do class I drugs have a greater effect in tachycardia?

Answer 31

more time in open and inactivated state

Question 32

What is the mechanism of action of digoxin?

Answer 32

stimulates vagal activity - slows conduction and prolongs refractory period in AV node and bundle of His

Question 33

What class is amiodarone?

Answer 33

class III, has class IA, II and IV actions

Question 34

What is amiodarone used for?

Answer 34

supraventricular and ventricular tachycardia, congestive heart failure, reduces mortality post MI

Question 35

What is flecainide used for?

Answer 35

prophylaxis of paroxysmal atrial fibrillation

Question 36

What is the mechanism of action of class II drugs?

Answer 36

decrease rate of depolarisation in SA and AV nodes

Question 37

What class is dispoyramide?

Answer 37

IA

Question 38

What class of drugs are beta blockers?

Answer 38

class II

Question 39

Why do class I drugs act preferentially on ischaemic tissues?

Answer 39

longer AP duration - more time in inactivate state

Question 40

What class id procainamide?

Answer 40

class IA

Question 41

How is verapamil administered?

Answer 41

oral

Question 42

What class is flecainide?

Answer 42

class IC

Question 43

Why is amiodarone pro arrhythmic?

Answer 43

Lengthens QT interval