DC Pharmacology & Drug Administration 3

Question 1

Which Class III antiarrhythmic drug has both beta-blocking and potassium channel-blocking properties?

Accepted Answer

Sotalol

Answer

Sotalol is unique in that it combines non-selective beta-blockade (Class II) with potassium channel blockade (Class III), prolonging the action potential duration.

Question 2

When atropine is administered to a patient with symptomatic bradycardia, its primary mechanism is:

Accepted Answer

Competitive antagonism of muscarinic (M2) receptors, removing vagal inhibition

Answer

Atropine competitively blocks muscarinic M2 receptors, removing parasympathetic (vagal) inhibition and thereby increasing heart rate.

Question 3

Ibutilide (Corvert) is FDA-approved primarily for:

Accepted Answer

Acute pharmacologic cardioversion of recent-onset atrial fibrillation or flutter

Answer

Ibutilide is a Class III antiarrhythmic approved for rapid pharmacologic conversion of atrial fibrillation or flutter of recent onset (within 7 days).

Question 4

A patient in stable VT receives lidocaine 1.5 mg/kg IV bolus with no effect. The correct next step regarding lidocaine is:

Accepted Answer

Give an additional 0.5–0.75 mg/kg IV bolus and reassess

Answer

Current ACLS guidelines allow repeat lidocaine boluses of 0.5–0.75 mg/kg IV every 5–10 minutes (max 3 mg/kg total) if the initial bolus is ineffective.

Question 5

Which of the following is a pharmacologic effect UNIQUE to dronedarone compared to amiodarone?

Accepted Answer

It lacks iodine moieties, reducing thyroid and pulmonary toxicity

Answer

Dronedarone was developed as a non-iodinated analog of amiodarone, eliminating thyroid and pulmonary toxicities, though it is less effective and contraindicated in heart failure.

(DC) Dysrhythmia Certification Practice Test

(DC) Dysrhythmia Certification Practice Test

DC Pharmacology & Drug Administration 3