Exam 6 - Antiarrhythmic Drugs Flashcards

1
Q

Causes of arrhythmias: abnormal automaticity

A
  • enhanced automaticity of SA node
  • damaged myocardial cells
  • after-depolarization (abnormal impulses) triggered by abnormal calcium influx provoked by digoxin toxictiy
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2
Q

Causes of arrhythmias: abnormalities in impulse conduction

A
  • reentry (most common cause of arrhythmias)

- unidirecitonal

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3
Q

Drug induced arrhythmias

A
  • Sympathetic drugs
  • Hypokalemia increase automaticity
  • Digoxin
  • Antiarrhythmic, antipsychotic drugs (ziprasadone)
  • DO NOT USE ANTIARRHYTHMICS IN HF
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4
Q

Drug induced arrhythmias: Sympathetic drugs

A
  • increase automaticity of SA and AV

- produces tachyarrhythmia

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5
Q

Drug induced arrhythmias: Digoxin

A
  • evokes after-depolarization (abnormal impulses) by increasing calcium influx into cardiac cells - can lead to extrasystole and tachycardia (toxic concentration)
  • impair AV node conduction
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6
Q

Drug induced arrhythmias: antiarrythmias, antipsychotic drugs

A

slow ventricular repolarization and cause QT prolongation evokes torsade de pointes

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7
Q

When should you not use antiarrhythmic?

A

Do not use antiarrhythmic in HF (except Amiodarone and Dofetilide)

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8
Q

Class IA

A

Na+ channel blocker

K+ channel blocker

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9
Q

Class IB

A

Na+ channel blocker

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10
Q

Class IC

A

Na+ channel blocker

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11
Q

Class II

A

B-adrenergic blocker

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12
Q

Class III

A

K+ channel blocker

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13
Q

Class IV

A

Ca2+ channel blocker

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14
Q

Procainamide

A

Class I Na+ channel blocker

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15
Q

Procainamide MOA

A

binds to sodium and potassium channels

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16
Q

Procainamide indiations

A

ACLS guidelines

- stable Wide-QRS tachycardia (ventricular arrhythmia

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17
Q

Procainamide adverse effects

A
  • systemic lupus erythematosus

- Torsade de pointes

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18
Q

Lidocaine

A

Class IB

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19
Q

What is Lidocaine?

A

Local anesthetic and has antiarrhythmic activity (more pronounced effect on ischemic tissue)

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20
Q

Lidocaine indications

A
  • ACLS guidelines
  • ALTERNATIVE TO AMIODARONE IN VENTRICULAR FIBRILLATION (VF)
  • pulseless ventricular tachycardia (PVT)
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21
Q

Propafenone

A

Class IC

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22
Q

Propafenone pharmacokinetics

A

Beta-blocker properties

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23
Q

Propafenone indications

A

Atrial fibrillation (AF)

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24
Q

Propafenone adverse effects

A

Bronchospasms

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25
Q

Propafenone drug interactions

A

increase digoxin levels (toxicity)

26
Q

Metoprolol

Atenolol

A

Class II drugs: B-blockers

27
Q

Metoprolol and Atenolol MOA

A

inhibit sympathetic activation of cardiac automaticity and conduction

28
Q

Metoprolol and Atenolol Indications

A

ACLD guidelines

  • stable narrow QRS irregular rhythm (narrow = atrial arrhythmia)
  • stable narrow QRS regular rhythm not controlled by adenozine
29
Q

Amiodarone

A

Class III

30
Q

Amiodarone MOA

A
  • blocks potassium channel

- infrequently causes torsades de pointes

31
Q

Amiodarone pharmacokinetics

A
  • inhibits many CYP 450 isoenzymes

- long onset of action (half-life 40 days)

32
Q

Amiodarone indications

A

ACLS guidelines

  • VF/pulseless VT unresponsive to CPR, defibrillation, and vasopressor therapy
  • stable VT
  • ATRIAL FIBRILLATION (PATIENTS W/ HF)
33
Q

Amiodarone interactions

A

inhibits 1A2, 2C9, 2D6, and 3A4

  • digoxin
  • warfarin
  • lovastatin and simvastatin
34
Q

Amiodarone adverse effects

A
  • hypotension
  • blue-gray discoloration (smurf syndrome)
  • photosensitivity
  • thyroid abnormalities (hypo or hyperthyroidism)
  • increase in liver enzymes
  • pulmonary fibrosis, pneumonitis
  • corneal deposits
  • optic neuritis
35
Q

Ibutilide

A

Class III

36
Q

Ibutilide MOA

A

blocks potassium channel

37
Q

Ibutilide indications

A

conversion of AF to normal sinus rhythm

38
Q

Ibutilide adverse effects

A

torsades de pointes

39
Q

Dofetilide

A

Class III

40
Q

Dofetilide MOA

A

blocks potassium channel

41
Q

Dofetilide indications

A
  • atrial fibrillation (AF) [CAD and HF; must initiate in hospital]
  • renal dosage adjustment
42
Q

Dofetilide adverse effects

A

Torsade de pointes (due to QT prolongation)

43
Q

Sotalol

A

Class III

44
Q

Sotalol MOA

A

blocks potassium channel

45
Q

Sotalol indications

A
ACLS guidelines
- stable wide-QRS tachycardia (VT)
Atrial arrhythmias (AF)
46
Q

Sotalol adverse effects

A
  • torsades de pointes (due to QT prolongation)
  • bronchospasms
    DO NOT USE IN HF
47
Q

Ditliazem and Verapamil

A

nondyhydropyridine

48
Q

Diltiazem and Verapamil indications

A

ACLS guidelines

  • stable narrow QRS irregular rhythm
  • stable narrow QRS regular rhythm not controlled by adenosine
49
Q

Adenosine pharmacokinetics

A

administered IV bolus; extremely short half-life (10 sec)

50
Q

Adenosine MOA

A

activates adenosine receptors

51
Q

Adenosine indication

A

ACLS guidelines

  • stable, narrow complex regular tachycardia
  • stable, regular, monomorphic, wide complex tachycardia as a therapeutic and diagnostic maneuver
52
Q

Adenosine adverse effects

A
  • flushing
  • hypotension
  • bronchospasm, dyspnea
  • chest discomfort
53
Q

When should you avoid adenosine?

A

patients w/ asthma

54
Q

Digoxin and Magnesium sulfate (having to do w/ magnesium)

A
  • magnesium deficiency can contribute to arrhythmias
  • ACLS guidelines: torsade de pointes
  • Adverse effects: hypotension, CNS toxicity, respiratory depression
55
Q

Atrial fibrillation: rate control

A
  • B-blocker
  • calcium channel blockers (nondihydropyridine)
  • digoxin
56
Q

Atrial fibrillation: rhythmic control

A

antiarrhythmic drugs

57
Q

Antiarrhythmic drug therapy for AF (1st line): Normal or minimal heat disease

A

Propafenone

Sotalol

58
Q

Antiarrhythmic drug therapy for AF (1st line): HTN w/o LVH

A

Propafenone

Sotalol

59
Q

Antiarrhythmic drug therapy for AF (1st line): HTN w/ LVH

A

Amiodarone

60
Q

Antiarrhythmic drug therapy for AF (1st line): HF

A

Amiodarone

Dofetilide

61
Q

Antiarrhythmic drug therapy for AF (1st line): CAD

A

Sotalol

Dofetilide