Car 11 - Antiarrhythmics

Question 1

What are the 4 types of antiarrhythmics?

Answer 1

[No Bad Boy Keeps Clean] No: Na+ channel blockers (I). Bad boy: beta blockers (II). Keeps: K+ channel blockers (III). Clean: Ca2+ channel blockers (IV).

Question 2

What are class I antiarrhythmics going to do to the ventricular action potential phases?

Answer 2

It decreases the slope of phase 0, therefore elongating the effective refractory period.

Question 3

What are three Class 1A antiarrhythmics?

Answer 3

[Double Quarter-Pounder] Disopyramide. Quinidine. Procainamide.

Question 4

What are three Class 1B antiarrhythmics?

Answer 4

[Mayo, Lettuce, Tomato] Mexiletine. Lidocaine. Tocainide.

Question 5

What are three Class 1C antiarrhythmics?

Answer 5

[Fries, Please] Flecainide, Propafenone.

Question 6

What drugs do we use for Wolff-Parkinson-White (WPW)?

Answer 6

Procainamide (Class 1A antiarrhythmics). Amiodorone (Class III antiarrhythmic).

Question 7

What are two things about Procainamide?

Answer 7

Used in Wolff-Parkinson-White (WPW). Can cause a reversible SLE-like syndrome.

Question 8

What five drugs can cause drug-induced Lupus?

Answer 8

[SHIPP] Sulfonamides. Hydralazine. Isoniazid. Procainamide. Phenytoin.

Question 9

What three side effects can Quinidine cause?

Answer 9

Cinchonism (Headache, Dizziness, Tinnitus). Thrombocytopenia. Torsades de Pointes (increase in QT interval).

Question 10

What three settings do we use Lidocaine as an antiarrhythmic?

Answer 10

Acute ventricular tachyarrhythmias. Digitalis-induced arrhythmias. Tachyarrhythmias post-MI.

Question 11

What does hyperkalemia do in the use of antiarrhythmics?

Answer 11

Can increase their toxicities.

Question 12

What 5 beta-blockers are used as antiarrhythmics?

Answer 12

Propanolol. Esmolol. Metoprolol. Atenolol. Timolol.

Question 13

What is the MOA of beta blockers as antiarrhythmics?

Answer 13

They decrease cyclic AMP and decrease calcium currents. So they increase the PR interval and suppress abnormal pacemakers by decreasing the slope of phase 4 (In the pacemaker action potential).

Question 14

What are 5 side effects of beta blocker?

Answer 14

Exacerbation of asthma. Bradycardia. AV block. CHF exacerbation. Mask effect of hypoglycemia.

Question 15

What is the treatment for beta-blocker overdose?

Answer 15

Glucagon.

Question 16

What are class III antiarrhythmics going to do to the ventricular action potential phases?

Answer 16

Work on phase 3. It slows down the release of potassium, thereby elongating the effective refractory period, increasing action potential duration, and the QT interval.

Question 17

What are five class III antiarrhythmic drugs?

Answer 17

Amiodarone. Ibutilide. Sotalol. Bretylium. Dofetilide.

Question 18

What are three potential side effects of Amiodarone?

Answer 18

Pulmonary fibrosis. Hepatotoxicity. Hypo- or hyperthyroidism (Amiodarone is 40% iodine by weight). [When using amiodorone, use your PFTs, LFTs, and TFTs.] Can also cause corneal deposits, and skin (blue-grey) depositis (photodermatitits). Can also cause neurologic effects, constipation, CV (bradycardia, heart block, heart failure).

Question 19

What three drugs cause photosensitivity?

Answer 19

[SAT for photo] Sulfonamides. Amiodarone. Tetracycline.

Question 20

What are the 2 subclasses of class 4 antiarrhythmic drugs (Ca2+ channel blockers)?

Answer 20

Non-dihydropyridine (work on the heart): Verapamil, Diltiazem. Dihydropyridine (work at the periphery): Nifedipine, Felodipine, Amlodipine.

Question 21

How do non-dihydropyridine Ca2+ channel blockers work as antiarrhythmics?

Answer 21

They decrease the slope of phase 0 of the ventricular action potential, elongating effective refractory period. There is a decrease in conduction velocity in AV nodes as well.

Question 22

What are four side effects of Ca2+ channel blockers?

Answer 22

Constipation. Flushing. Edema. CV (heart failure, AV block, Sinus node depression, Torsades de Pointes).

Question 23

How does Adenosine work as an antiarryhthmic?

Answer 23

Increases the K+ leaving the cell, hyperpolarizing the cell. Decreases the permeability of Ca2+ as well (decreases intracellular Ca2+).

Question 24

When do we use adenosine as antiarrhythmic?

Answer 24

Supraventricular tachycardia(SVT) (can help both diagnose it and treat it).

Question 25

What are the side effects of Adenosine?

Answer 25

Flushing. Hypotension. Angina.

Question 26

How do we block the effects of Adenosine?

Answer 26

Theophylline.

Question 27

What levels should K+/Mg+ be, especially for post-MI patients?

Answer 27

K+: Above 4. Mg+: above 2. Because they are predisposed to arrythmias.

Question 28

Which antiarrhythmic has the side effect of cinchonism?

Answer 28

Quinidine.