[INCOMPLETE] Antiarrhythmic drugs

Question 1

Class I antiarrhythmic agents act on which ion channels?

Answer 1

Na+ channels

Question 2

Class II antiarrhythmic act on which receptors?

Answer 2

Beta-receptors

Question 3

Class III antiarrhythmic agents act on which ion channels?

Answer 3

K+ channels

Question 4

Class IV antiarrhythmic agents act on which ion channels?

Answer 4

Ca2+ channels

Question 5

Which class of antiarrhythmic agents act on Na+ channels?

Answer 5

Class I

Question 6

Which class of antiarrhythmic agents act on Beta-receptors?

Answer 6

Class II

Question 7

Which class of antiarrhythmic agents act on K+ channels?

Answer 7

Class III

Question 8

Which class of antiarrhythmic agents act on Ca2+ channels?

Answer 8

Class IV

Question 9

What effect do group IA antiarrhythmic agents have on AP duration?

Answer 9

Prolong AP duration

Question 10

What effect do group IB antiarrhythmic agents have on AP duration?

Answer 10

Slightly shorten AP duration in ischemic tissue

Question 11

What effect do group IC antiarrhythmic agents have on AP duration?

Answer 11

No effect on AP duration

Question 12

Group IA antiarrhythmic agents dissociate with what kinetics?

Answer 12

Intermediate kinetics

Question 13

Group IB antiarrhythmic agents dissociate with what kinetics?

Answer 13

Rapid kinetics

Question 14

Group IC antiarrhythmic agents dissociate with what kinetics?

Answer 14

Slow kinetics

Question 15

What is the group IA antiarrhythmic agent prototype?

Answer 15

Procainamide

Question 16

Procainamide is the prototype of which class of antiarrhythmic agent?

Answer 16

Group IA

Question 17

Group IA antiarrhythmic agents have what effects on Purkinje fiber action potentials?

Answer 17

Slow upstroke of AP, prolong AP duration, increase refractory period

Question 18

Group IA antiarrhythmic agents cause what changes seen on EKG?

Answer 18

QRS prolongation, QT prolongation

Question 19

What are the common side effects of group IA antiarrhythmic agents?

Answer 19

Torsades de pointe (more likely in hypokalemic patients), lupus-like syndrome, thrombocytopenia

Question 20

What effect does hyperkalemia have on cardiac toxicity of class I antiarrhythmic agents?

Answer 20

Exacerbates cardiac toxicity by increasing blockade of NA+ channels

Question 21

Group IA antiarrhythmic agents are contraindicated in patients that are taking what drugs?

Answer 21

Drugs that cause hypokalemia or prolong AP duration (increased risk of Torsade de Pointes)

Question 22

Procainamide is given to patients in which form?

Answer 22

IV only

Question 23

What is the group IB prototype antiarrhythmic agent?

Answer 23

Lidocaine

Question 24

Lidocaine and mexiletine belong to which class of antiarrhythmic agents?

Answer 24

Group IB

Question 25

Lidocaine is given to patients in which form?

Answer 25

IV only

Question 26

Mexiletine is given to patients in which form?

Answer 26

Oral only

Question 27

Class IB antiarrhythmic agents have what effects on Purkinje fiber action potentials?

Answer 27

Little effect on normal tissue due to rapid dissociation; slow upstroke of AP, shortened AP duration in ischemic tissue

Question 28

Group IB antiarrhythmic agents cause what changes on EKG?

Answer 28

Slight shortening of QT interval

Question 29

What are the common side effects of group IB antiarrhythmic agents?

Answer 29

Restlessness, tremor, convulsions, respiratory/cardiovascular depression

Question 30

Group IB antiarrhythmic agents are contraindicated in patients taking which drugs?

Answer 30

Drugs that decrease seizure threshold or cause hyperkalemia

Question 31

What is the group IC prototype antiarrhythmic agent?

Answer 31

Flecainide

Question 32

Flecainide is the prototype for which class of antiarrhythmic agent?

Answer 32

Group IC

Question 33

Group IC antiarrhythmic agents have what effects on Purkinje fiber action potentials?

Answer 33

Slow upstroke of AP without AP prolongation

Question 34

Group IC antiarrhythmic agents cause what changes on EKG?

Answer 34

Increase QRS duration

Question 35

What are the major side effects of group IC antiarrhythmic agents?

Answer 35

Exacerbation of heart failure, increase mortality post acute MI, can cause cardiac arrest in patients with prolonged QRS

Question 36

What are the uses of group IC antiarrhythmic agents?

Answer 36

Treatment of supraventricular arrhythmias in patients without structural or ischemic alterations of the heart

Question 37

What are the uses of group IB antiarrhythmic agents?

Answer 37

Treatment of ventricular arrhythmias caused by acute ischemia or digoxin toxicity

Question 38

What are the uses of group IA antiarrhythmic agents?

Answer 38

Treatment of all types of arrhythmias, especially in acute phase of myocardial infarction