Drugs for tachyarrhythmia management

Question 1

What type of drug is Quinidine?

Answer 1

Class Ia Na+ channel blocker

Question 2

What type of drug is Procainamide?

Answer 2

Class Ia Na+ channel blocker

Question 3

What type of drug is Lidocaine (IV)?

Answer 3

Class Ib Na+ channel blocker

Question 4

What type of drug is Mexiletine (PO)?

Answer 4

Class Ib Na+ channel blocker

Question 5

What type of drug is Propranolol?

Answer 5

Class II beta-adrenergic receptor blocker

Question 6

What type of drug is Atenolol?

Answer 6

Class II beta-adrenergic receptor blocker

Question 7

What type of drug is Esmolol?

Answer 7

Class II beta-adrenergic receptor blocker

Question 8

What type of drug is Metoprolol?

Answer 8

Class II beta-adrenergic receptor blocker

Question 9

What type of drug is Amiodarone?

Answer 9

Class III K+ channel blocker

Question 10

What type of drug is Sotalol?

Answer 10

Class III K+ channel blocker

Question 11

What type of drug is Diltiazem (IV and PO)?

Answer 11

Class IV Ca++ channel blocker

Question 12

What drugs would you use for ventricular tachyarrhythmia?

Answer 12

Na+ channel blockers, K+ channel blockers, beta blockers

Question 13

What drugs would you use for supraventricular arrhythmia (A-fib, SVT)?

Answer 13

Class Ia Na+ channel blockers, beta blockers

Question 14

What is the effect of class Ia Na+ channel blockers?

Answer 14

Prolongs AP duration (atrial and ventricular cells)

Question 15

What is the effect of class Ib Na+ channel blockers?

Answer 15

Shortens AP duration (ventricular cells primarily)

Question 16

What is the effect of beta blockers?

Answer 16

Slows AV nodal conduction > slows ventricular response rate > decreases contractility

Reduces myocardial oxygen demand

Question 17

What is the effect of K+ channel blockers?

Answer 17

Prolongs AP and refractory period (interrupt re-entry)

Question 18

What is the effect of Ca++ channel blockers?

Answer 18

Blocks L-type calcium channel > decreases ventricular response rate by slowing AV nodal conduction (interrupt re-entry)

Also works on SA node

Question 19

What is the side effect of using class Ia Na+ channel blockers?

Answer 19

1. GI effects

2. Quinidine: increases digoxin levels

Question 20

What is the side effect of using class Ib Na+ channel blockers?

Answer 20

1. CNS effects (depression, seizures)

2. CAUTION IN CATS! (glurcuronide; have to give 1/10th - 1/20th dose)

Question 21

What is the side effect of using beta blockers?

Answer 21

1. Negative inotrope
2. Ngative chronotrope
3. Worsening of asthma (cats)

Question 22

What is the side effect of using K+ channel blockers?

Answer 22

1. Sotalol: negative inotrope

Bradycardia and prolonged QT in humans

Question 23

What is the side effect of using Ca++ channel blockers?

Answer 23

1. Negative inotrope
2. Bradycardia
3. AV block
4. GI upset (cats don’t deal with this well)

Question 24

What is used to treat life-threatening ventricular tachycardia?

Answer 24

Lidocaine

Question 25

What is the first line for ventricular arrhythmia in cats?

Answer 25

Beta blockers (Atenolol, Esmolol)

Question 26

What is used prophylactically for ventricular arrhythmias in semilunar valve stenosis?

Answer 26

Beta blockers