Chapter 45 Antiarrhythmic Agents

Chapter 45  Antiarrhythmic Agents

Complete Chapter Questions And Answers
 

Sample Questions

1.
A patient with a history of atrial fibrillation has had a worsening of his or her condition. The nurse knows that the drug of choice for long-term stabilization of atrial fibrillation following electrocardioversion is what?
A)
Disopyramide (Norpace)
B)
Moricizine (Ethmozine)
C)
Procainamide (Pronestyl)
D)
Quinidine (generic)
Ans:
D

Feedback:

Quinidine is often the drug of choice for long-term stabilization of atrial fibrillation after the rhythm is converted by electrocardioversion. Quinidine is a class I antiarrhythmic and stabilizes the cell membrane by binding to sodium channels, depressing phase 0 of the action potential, and changing the duration of the action potential. Disopyramide, moricizine, and procainamide are all used in the treatment of life-threatening ventricular arrhythmias.

2.
What class of antiarrhythmics drug blocks potassium channels, prolonging phase 3 of the action potential and slowing the rate and conduction of the heart?
A)
I
B)
II
C)
III
D)
IV
Ans:
C

Feedback:

The class III antiarrhythmics block potassium, prolonging phase 3 of the action potential, which prolongs repolarization and slows the rate and conduction of the heart. Class I drugs block the sodium channels in the cell membrane during an action potential. Class II drugs are beta-adrenergic blockers that block beta-receptors, causing a depression of phase 4 of the action potential. Class IV drugs block calcium channels in the cell membrane leading to a depression of depolarization and a prolongation of phases I and II of repolarization, which slows automaticity.

3.
The nurse is caring for a pediatric patient who has been diagnosed with paroxysmal atrial tachycardia. The order reads digoxin 10 mcg/kg orally. The child weighs 44 pounds. How many mcg will the nurse administer?
A)
50 mcg
B)
100 mcg
C)
150 mcg
D)
200 mcg
Ans:
D

Feedback:

The nurse will administer 200 mcg. (2.2 pounds: 1 kg = X: 20 kg, 20(10) = 200 mcg).

4.
The nurse is providing drug teaching about quinidine in preparation for the patient’s discharge. The nurse discusses drug–food interactions and advises the patient to drink what?
A)
Apple juice
B)
Grapefruit juice
C)
Milk
D)
Orange juice
Ans:
A

Feedback:

Apple juice would be the best choice. Quinidine requires a slightly acidic urine (normal state) for excretion. Patients receiving quinidine should avoid foods that alkalinize the urine (e.g., citrus juices, vegetables, antacids, milk products), which could lead to increased quinidine levels and toxicity. Grapefruit juice has been shown to interfere with the metabolism of quinidine, leading to increased serum levels and toxic effects; this combination should be avoided.

5.
A patient has had sotalol (Betapace) ordered for treatment of a ventricular arrhythmia. What will the nurse consider when administering the drug?
A)
Sotalol has a very short duration of action
B)
Food increases the bioavailability of the drug
C)
Absorption of sotalol is decreased by the presence of food
D)
The drug is best administered intramuscularly
Ans:
C

Feedback:

This drug should not be taken with food because absorption is decreased. The drug should be given 1 hour before or 2 hours after a meal. Adenosine, not sotalol, has a very short duration of action and food increases the bioavailability of propranolol. Sotalol is administered by oral route only.