Anti Arrhythmics

Question 1

Na Channel Blockers: Class 1a

Answer 1

Moderate blockade, K channel blockade,GI side effects, nausea, Lupus, increased LFT, diarrhea, anticholinerigics, strong negative inotrope

Question 2

Na Channel Blockers Class 1a drugs

Answer 2

Procainamide, Quinidine, Disopyramide

Question 3

Na Channel Blockers:Class 1b

Answer 3

Weak blockade (pH and rate dependent), 
Faster the rate, the stronger the Na channel blockade effect
The lower the pH, the stronger the Na channel blockade

Question 4

Na Channel Blockers class 1b drugs

Answer 4

Lidocaine and Mexiletine

Question 5

Na Channel Blockers: Class 1c

Answer 5

strong blockade, beta blockade, negative inotrope and bad for asthma patients

Question 6

Na Channel Blocker Class 1c Drugs

Answer 6

Flecainide and Propafenone

Question 7

Class 1 contraindications

Answer 7

Both class 1a and 1c should not be used in patients with any cardiac structural abnormalities
Class 1b is excellent in ventricular arrhythmias because of Ischemia (but not in atrial fibrillation)

Question 8

Class II: Beta Blockers

Answer 8

Metoprolol and Atenolol

Question 9

Class II MOA

Answer 9

Suppression of abnormal pacemaker activity by blocking sympathetic (B1 receptor) activity in SA/AV node
Membrane stabilization effects

Question 10

Class II ADRs

Answer 10

Hypotension, Bradycardia, Exercise Intolerance, Sexual Dysfunction, Negative inotrope

Question 11

Class II clinical considerations

Answer 11

Use to control ventricular rate in patients with supra ventricular arrhythmias
Use in preventing ventricular arrhythmias post MI or in HF patients

Question 12

Class II contraindications

Answer 12

patients with severe asthma

Question 13

Class III: Potassium Channel Blockers MOA

Answer 13

block potassium channel to delay repolarization, increase in refractory period

Question 14

Class III: Sotalol

Answer 14

Combine Beta blocker and Potassium channel blocker
Requires renal dosage adjustment
Side Effects: proarrhythmias
Hospital for QT interval

Question 15

Class III: Dofetilide

Answer 15

Minimal negative inotrope effect
Requires renal dosage adjustment
QT monitoring in hospital
side effects: well tolerated except for proarrhythmias

Question 16

Class III: Ibutilide

Answer 16

IV only, treats acute Afib, high risk of Torsades especially with patients with structural cardiac abnormalities

Question 17

Class III: Dronedarone

Answer 17

Amiodarone analog but they lack iodine atoms
May also have Ca, Na, and Beta blocker effect
Increases mortality in HF and chronic AFib patients
side effect: least proarrhythmic

Question 18

Class III: Amiodarone

Answer 18

Most effective AAD
Minimal negative inotrope effect
Large volume of distribution
very long half life
minimal proarrhythmic effect

Question 19

Amiodarone toxicities

Answer 19

affects all systems (eyes, liver, GI skin, brain, heart, lungs) except kidneys

Question 20

Amiodarone major DDI

Answer 20

Digoxin - decrease dose by 50%
Warfarin - decrease dose by 30-50%
Simvastatin - max dose 20 mg/day

Question 21

Class IV: Calcium Channel Blockers

Answer 21

Non DHPs: Verapamil and Diltiazem

Question 22

Class IV MOA

Answer 22

Slows conduction in AV node by blocking Calcium channel, slow ventricular rate

Question 23

Class IV ADR

Answer 23

Constipation, Hypotension, Bradycardia, Negative Inotropes, Exacerbation of HF

Question 24

Class IV DDI

Answer 24

Statins and Digoxin

Question 25

Digoxin MOA

Answer 25

Inhibitor of Na/K ATPase pump which provides positive inotropic effect
Increase Parasympathetic NS activities (slows HR and everything)

Question 26

Digoxin Side Effects

Answer 26

GI- nausea and vomiting
Neurological- CNS, Yellow Green Halo
Cardiac Toxicity arrhythmias

Question 27

Digoxin DDIs

Answer 27

Quinidine
Amiodarone
Verapamil
Dose Adjustment in Renal Function

Question 28

Adenosine

Answer 28

IV only; short duration of action (10-15 seconds)

Question 29

Adenosine MOA

Answer 29

slow AV node conduction via binding to adenosine receptor

Question 30

Adenosine ADR

Answer 30

Vasodilation (Flushing, Hypotension), Chest Pain, Dyspnea (adenosine receptor reaction in lung)