Anti-arrhythmia

Question 1

What class of drugs are in Class 1?

Answer 1

Sodium channel blockers

Question 2

What class of drugs are in Class 2?

Answer 2

Beta-blockers

Question 3

What class of drugs are in Class 3?

Answer 3

Potassium channel blockers

Question 4

What class of drugs are in Class 4?

Answer 4

Calcium Channel Blockers

Question 5

Name the drugs in Class 1A

Answer 5

• Quinidine
• Procainamide
• Disopyramide

Question 6

Name the drugs in Class 1B

Answer 6

• Lidocaine

- Mexiletine

Question 7

Name the drugs in Class 1C

Answer 7

• Flecainide

- Propafenone

Question 8

What is the MOA of the Class 1A drugs?

Answer 8

Prolong the duration of the action potential and the effective refractory period

Question 9

True or False: Class 1B drugs have no significant effects on the duration of action potential?

Answer 9

True

Question 10

What is the MOA of Lidocaine?

Answer 10

Blocks activated and inactivated sodium channels and selectively depresses conduction in depolarized cells as a result of slower dissociation kinetics

Question 11

Name the toxicities of the Class 1B drugs

Answer 11

• Hypotension (at high doses)

- Tremor, nausea, hearing disturbances, and convulsions (dose-related and short lived)

Question 12

True or False: Class 1A drugs are safer than Class 1B drugs?

Answer 12

False; class 1B is safer

Question 13

What is the route of administration for lidocaine?

Answer 13

IV

Question 14

Which sodium channel blocker is the least cardiotoxic?

Answer 14

Lidocaine

Question 15

Prophylactic use of lidocaine may (increase or decrease?) mortality?

Answer 15

Increase

Question 16

True or False: Lidocaine is effective in arrhythmias with acute MI?

Answer 16

True

Question 17

What is the MOA of the class 1C drugs?

Answer 17

Minimal effects on the duration of the action potential

Question 18

What is the beta-blocker is used in the Class 2 drugs?

Answer 18

Esmolol

Question 19

What is the MOA of Esmolol?

Answer 19

Reduce the beta-adrenergic activity of the heart

Some will prolong the cardiac action potential

Question 20

True or False: Beta-blockers are less effective than sodium channel blockers

Answer 20

True

Question 21

True or False: Beta-blockers are sympatholytic drugs?

Answer 21

True

Question 22

Beta-blockers prevent recurrent infarction and sudden death in patients recovering from _________

Answer 22

acute MI

Question 23

Name the drugs in Class 3

Answer 23

• Amiodarone
• Dronedarone
• Sotalol
• Dofetilide
• Ibutilide

Question 24

What is the MOA of potassium channel blockers?

Answer 24

Prolong the duration of the action potential by blocking potassium channels in cardiac muscle resulting in prolonging the effective refractory period

Question 25

What is the MOA of amiodarone?

Answer 25

Prolongs the action potential by blocking potassium channels—blocks sodium channels which contributes to prolongation—weak adrenergic and calcium channel blocking agent which slows the HR and AV node conduction

Question 26

Name the toxicities of Class 3 drugs

Answer 26

- Bradycardia and heart block in patients with preexisting SA or AV node disease - Dose-related pulmonary toxicity - Alters blood levels of thyroid hormone

Question 27

How do Class 3 drugs alter blood levels of thyroid hormone?

Answer 27

blocks the peripheral conversion of thyroxine (T4) to triiodothyronine (T3) and is a potential source of iodine

Question 28

True or False: Amiodarone exhibits actions of all 4 classes but its predominant effect is sodium channel blocking?

Answer 28

False; potassium channel blocking

Question 29

Amiodarone's broad spectrum of actions account for (high or low?) efficacy and (high or low?) incidence of drug-induced arrhythmias

Answer 29

high; low

Question 30

True or False: Amiodarone is not use-dependent?

Answer 30

True

Question 31

Name some facts about Dronedarone

Answer 31

- Non-iodinated form of amiodarone - less lipophilic - shorter half-life - less effective and less toxic than amiodarone

Question 32

Name the class 4 drugs

Answer 32

- Verapamil | - Diltiazem

Question 33

What is the MOA of the calcium channel blockers?

Answer 33

Block the cardiac calcium current by blocking the calcium channel resulting in slowing conduction in the SA and AV nodes

Question 34

What is the MOA of verapamil?

Answer 34

Blocks the L-type calcium channels, it’s blocking action is use-dependent, prolongs the AV and SA node and the effective refractory period overall causing peripheral vasodilation

Question 35

Name the toxicities of Class 4 drugs

Answer 35

- Cardiotoxicity (dose-related) - Hypotension and ventricular fibrillation when given to patients with ventricular tachycardia - AV block (high-doses) in patients with AV nodal disease - Sinus arrest in patients with AV nodal disease - Constipation - Nervousness - Peripheral edema