Antiarrhythmic Drugs

Question 1

Group 1A drugs

Answer 1

Procainamide, Disopyramide, Quinidine

Question 2

MOA of group 1A drugs

Answer 2

Block both Na+ and K+ channels. Prolongs AP duration and refractory period (ERP).

Question 3

Group 1A drug whose toxicity includes lupus-like syndrome

Answer 3

Procainamide

Question 4

Group 1A drug whose toxicity includes cinchonism (tinnitus, headache, GI disturbances) and thrombocytopenia

Answer 4

Quinidine

Question 5

Group 1B drugs

Answer 5

Lidocaine, Mexiletine

Question 6

MOA of Group 1B drugs

Answer 6

Block Na+ channels with . Highly selective for ischemic tissue.

Question 7

Orally active group 1B drug

Answer 7

Mexiletine

Question 8

What is the most important use of lidocaine?

Answer 8

Emergency treatment of MI arrhythmias.

Also digoxin-induced arrhythmias

Question 9

Group 1C drug

Answer 9

Flecainide

Question 10

Most effective agents in acute thyrotoxicosis

Answer 10

beta blockers

Question 11

Most efficacious of all anti arrhythmic drugs. Broad spectrum: blocks Na, Ca, and K channels and beta receptors

Answer 11

Amiodarone

Question 12

Amiodarone toxicities

Answer 12

thyroid dysfunction, pulmonary fibrosis, paresthesias, tremor, optic neuritis, and microcrystalline deposits in the cornea and skin

Question 13

MOA of sotalol

Answer 13

Ik block and beta-rc block

Question 14

Adverse effect of most Group 3 arrhythmics

Answer 14

Torsades de Pointes

Question 15

Antiarrhythmic with the longest half-life (1-10 weeks)

Answer 15

Amiodarone

Question 16

Completely blocks conduction in the AV node, probably by increasing K conductance (i.e., hyper polarizing the tissue) and by reducing Ca2+ . Duration of action ~15 sec.

Answer 16

Adenosine