Exam 2 - Anti-arrhythmics

Question 1

What is the MOA for Quinidine of Class IA?

Answer 1

Blocks activated Na channels
Slows the rate of the AP in normal cells
No depolarization at all in damaged cells (good for ectopic pace makers)

Question 2

What are the uses of Quinidine?

Answer 2

• Acute or chronic treatment of supraventricular and ventricular arrhythmias

***rarely used though due to low therapeutic index and adverse effects

Question 3

What are adverse effects of Quinidine?

Answer 3

• Cardiac toxicity (SA/AV blocks, ventricular arrhythmia)
• Blocks alpha receptors leading to severe hypotension and reflex tachycardia
• Paradoxical tachycardia
• Torsade de pointes
• Increases QRS and QT on EKG
• Diarrhea, N/V (most common extracardic tox)
• Cinchonism (loss of hearing, angioedema, vertigo, tinnitus, visual disturbances, thrombocytopenic purpura)

Question 4

What is the MOA for Procainamide of Class IA?

Answer 4

Similar to Quinidine

Question 5

What are adverse effects of Procainamide?

Answer 5

Lupus erythematosus in slow acetylators (HIP drug)

Question 6

What is the MOA for Lidocaine of Class IB?

Answer 6

Blocks inactivated Na+ channels so that they cannot reset and become activated again, leading to no AP

Question 7

What is the DOC for ACUTE ventricular arrhythmias?

Answer 7

Lidocaine

Question 8

What are the uses of Lidocaine?

Answer 8

ACUTE ventricular arrhythmias?

Question 9

What are the adverse effects of Lidocaine?

Answer 9

• Convulsions and paresthesias

- Slows conduction, bradycardia

Question 10

What is the MOA for Flecainide of Class IC?

Answer 10

• Strongly blocks all Na+ channel states with slow dissociation from binding, leading to long/hard effects

Question 11

What are the uses of Flecainide?

Answer 11

• Supraventricular arrhythmias
• Life threatening ventricular arrhythmias

***Last ditch-effort drug due to strong pro-arrhythmic effect

Question 12

What are adverse effects of Flecainide?

Answer 12

Strong pro-arrhythmic effect

***Last-ditch effort drug for ventricular arrhythmias

Question 13

What are the uses of Esmolol (beta-blocker)?

Answer 13

• Acute treatment of PSVTs (2nd line)

***short half-life and IV only

Question 14

What is the 2nd line treatment of PSVTs?

Answer 14

Esmolol

Question 15

What are the uses of Amiodarone?

Answer 15

• DOC for ventricular arrhythmias (ACLS/long-term)

- Supraventricular arrhythmias

Question 16

What is the DOC for ventricular arrhythmias (ACLS/long-term)?

Answer 16

ACLS/long-term: Amiodarone

Question 17

What are adverse effects of Amiodarone?

Answer 17

• Slows sinus rate, conduction, and prolongs QT
• Pulmonary fibrosis
• Deposited in tissues, cornea (yellow-brown), skin (grayish-blue)
• Thyroid dysfunction (due to elevated iodine levels in the drug)

***while it does cause QT prolongation, it does not cause Torsades de Pointes and is the exception to the rule regarding the relation to prolonged QT

Question 18

What is the MOA for Sotalol of Class III?

Answer 18

K+ blocker which prolongs action potential duration

Non-selective B-blocker

Question 19

What are the uses of Sotalol?

Answer 19

Ventricular and supraventricular arrhythmias

Question 20

What are the adverse effects of Sotalol?

Answer 20

Torsade de Pointes

Question 21

What is the MOA of Verapamil and Diltiazem, CCBs of Class IV?

Answer 21

Block slow L-type cardiac calcium channels

Question 22

What are the uses of Verapamil and Diltazem in regards to arrhythmias?

Answer 22

• Reentrant supraventricular tachycardia
• PSVT
• Atrial fibrillation and flutter
• Marked effects on the SA and AV nodes

***useful in areas where calcium is used for depolarization and only effective in the atria

Question 23

What should you avoid giving in combination with Verapamil and Diltazem?

Answer 23

Avoid combination with B-blockers or will induce heart block

Question 24

What is the MOA for Adenosine?

Answer 24

Enhanced K+ conductance and inhibition of cAMP-induced calcium influx

Hyperpolarizes everything and resets the heart; makes AP impossible and stops the heart very briefly

Question 25

What are the pharmacokinetics of Adenosine and why is this important in regards to its MOA?

Answer 25

IV administration and very short half-life of about 10 seconds makes it short enough to stop the heart and reset it

Question 26

What are uses for Adenosine?

Answer 26

- Acute PSVT (DOC) - Acute wolff parkinson white syndrome (DOC) - Effective only for reentry arrhythmias

Question 27

What is the DOC for acute PSVT?

Answer 27

Adenosine

Question 28

What is the DOC for wolff parkinson white syndrome?

Answer 28

Adenosine

Question 29

What are adverse effects of Adenosine?

Answer 29

Flushing, shortness of breath, chest burning, hypotension, nausea (only last a few seconds though before resolving)

Question 30

What is the order of treatment that should be given for acute PSVT?

Answer 30

1st line: Adenosine 2nd line: Esmolol 3rd line: CCBs (IV)

Question 31

What is the order of treatment that should be given for chronic PSVT?

Answer 31

1st line: B-blockers | 2nd line: CCBs

Question 32

How is Magnesium administered?

Answer 32

IV

Question 33

What are uses for IV Magnesium?

Answer 33

- Torsade de Pointe (DOC) - Antiarrhythmic effect in those with normal magnesium levels - Digitalis induced arrhythmias - Management of seizures and/or hypotension

Question 34

What is the DOC for Torsade de Pointes?

Answer 34

IV Magnesium

Question 35

What are the uses of Potassium?

Answer 35

- Decreases action potential duration - Decreases conduction - Decreases pacemaker rate - Decreases pacemaker arrhythmogenesis (essentially prevents arrhythmias)

Question 36

Which classes cannot be used for BOTH supraventricular and ventricular arrhythmias?

Answer 36

- Class IV (supraventricular only) | - Class 1B/Lidocaine (ventricular only)

Question 37

Which meds are administered IV only, so are useful only in acute therapy?

Answer 37

- Lidocaine - Adenosine - Magnesium