Drugs Flashcards
What is the mechanism of Class I antiarrhythmics?
A: Sodium channel blockers that reduce the speed of depolarization in the heart.
What are the subclasses of Class I antiarrhythmics?
Class IA, IB, and IC.
Q: What is the effect of Class IA antiarrhythmics?
A: Moderate sodium channel blockade; prolongs action potential and refractory period.
Q: Give two examples of Class IA drugs
Quinidine, Procainamide.
Q: What is the mechanism of Class IB antiarrhythmics?
A: Weak sodium channel blockade; shortens action potential duration.
Q: Give two examples of Class IB drugs
A: Lidocaine, Mexiletine
Q: Give two examples of Class IB drugs
A: Lidocaine, Mexiletine.
Q: What is the mechanism of Class IC antiarrhythmics?
: Strong sodium channel blockade; minimal effect on action potential duration.
Q: What is the mechanism of Class IC antiarrhythmics?
: Strong sodium channel blockade; minimal effect on action potential duration.
Q: Give two examples of Class IC drugs
A: Flecainide, Propafenone
Q: What is the mechanism of Class II antiarrhythmics?
A: Beta blockers that reduce heart rate and conduction by blocking beta-adrenergic receptors.
Q: Give two examples of Class II drugs
A: Metoprolol, Esmolol
Q: What is the mechanism of Class III antiarrhythmics?
A: Potassium channel blockers that prolong repolarization and increase the refractory period.
Q: Give two examples of Class III drugs.
A: Amiodarone, Sotalol
Q: What is the mechanism of Class IV antiarrhythmics?
A: Calcium channel blockers that slow AV node conduction and reduce heart rate.
Q: Give two examples of Class IV drugs
A: Verapamil, Diltiazem
Q: What is the mechanism of adenosine in antiarrhythmic treatment?
A: Slows conduction through the AV node by hyperpolarizing the cell membrane
Q: What arrhythmia is adenosine commonly used to treat?
A: Supraventricular tachycardia (SVT).
Q: What is the mechanism of digoxin in antiarrhythmia?
A: Inhibits sodium-potassium ATPase, increasing intracellular calcium and vagal tone to slow AV node conduction.
Q: What is magnesium sulfate used to treat in antiarrhythmia?
A: Torsades de pointes and magnesium deficiency-related arrhythmias.
Q: What is a common side effect of Class IA antiarrhythmics?
A: Risk of torsades de pointes due to QT prolongation.
: What are the main uses of Class II antiarrhythmics?
A: Supraventricular tachycardia (SVT), atrial fibrillation, and post-myocardial infarction prevention of sudden cardiac death.
Q: What is the major side effect of amiodarone, a Class III drug?
A: Pulmonary fibrosis, thyroid dysfunction, and liver toxicity.
Q: What is the major proarrhythmic risk associated with Class III drugs like sotalol?
A: QT prolongation and risk of torsades de pointes.
Q: Which class of antiarrhythmics primarily affects the AV node?
A: Class IV (Calcium channel blockers).
