Antiarrhythmics Flashcards Preview

Pharm II MHM - FINAL > Antiarrhythmics > Flashcards

Flashcards in Antiarrhythmics Deck (97):
1

What are non-VW agents used in arrhythmias?

Adenosine and digoxin

2

Describe the Vaughan Williams classification of antiarrhythmics

Class I = Na channel blockers
Class II = Beta blockersC
lass III = K channel blockers
Class IV = CCBs
Class V = variable mechanisms (adenosine, digoxin)

3

Class IA antiarrhythmics

Procainamide
Quinidine
Disopyramide
(Na channel blockers)

4

Class IB antiarrhythmics

Lidocaine
Mexilitine
(Na channel blockers)

5

Class IC antiarrhythmics

Flecainide
Propafenone
(Na channel blockers)

6

Which Class I antiarrhythmics should NOT be used after IC?

IA

7

Effects of Class IA drugs

-Reduces AP duration and ventricular refractoriness
-Increases repolarization

8

Effects of Class IB drugs

Shortens AP duration, ventricular refractoriness and repolarization

9

Effects of Class IC drugs

Markedly slows depolarization without affecting repolarization

10

Procainamide (class, indications, key features)

-Class IA Na channel blocker
-Stable monomorphic VT, VT w/accessory pathway, non-VT/VF arrest
-IV only!

11

Procainamide ADRs

-Peripheral vasodilation
-Hypotension
-Reflex tachy
-Arrest

12

How is procainamide metabolized? What is its half life?

-CYP2D6
-2.5 to 8 hours (NAPA metabolite 5-9 hours)

13

How is procainamide dosed in renal and hepatic impairments?

-Lower loading dose in renal
-Cut all doses 50% in hepatic

14

What drugs interact with procainamide?

-Tricyclics
-SSRIs
-Opioids

15

Procainamide serious adverse events

-Heart block, widening QRS, Torsades
-Hepatotoxicity
-Drug induced lupus

16

Disopyramide (class, indications, key features)

-Class IA Na channel blocker
-Stable monomorphic VT, AF conversion
-Used as an alternative to procainamide
-A/w cardiogenic shock

17

How is disopyramide metabolized? What is its half life?

-CYP3A4, significant 1st pass
-Half life 4-10 hours

18

How is disopyramide dosed?

Weight based

19

When is disopyramide adjusted in renal impairment?

CrCl less than 40 mL/min

20

Disopyramide serious adverse events

-Torsades, HF, hypotension
-Xerostomia
-Urinary hesitancy
-Constipation
-Rash

21

Disopyramide contraindications

-AV block
-QT prolongation
-Cardiogenic shock

22

Disopyramide has significant ____ effects, so it should be avoided in patients with _____

-Anticholinergic
-Avoid in glaucoma and myasthenia gravis

23

Quinidine (class, indications, key features)

-Class IA Na channel blocker
-Maintenance of sinus rhythm when LV function is preserved
-NOT used for ventricular arrhythmias

24

How is quinidine metabolized?

-CYP3A4
-Metabolite has antiarrhythmic effects that need to be accounted for

25

Quinidine serious adverse events

-Arrhythmias, QT prolonged, Torsades
-GI issues
-Dizzy, HA, tremor

26

Quinidine contraindications

-WPW
-AV block
-Digitalis toxicity
-Myasthenia gravis

27

Lidocaine (class, indications, key features)

-Class IB Na channel blocker
-VT/VF when defib/epi fails and amiodarone unavailable
-Digoxin induced VT, monomorphic VT
-Efficacy is reduced over duration of arrest
-"Safest" of all Na channel blockers

28

What is the safest of all Na channel blockers?

Lidocaine

29

How is lidocaine metabolized? What is its half life?

-CYP1A2, hepatic blood flow determines rate (significantly impaired during arrest)
-1.8 hours

30

Lidocaine serious adverse events

-Arrhythmias
-Seizure, tremor, paresthesias

31

Mexiletine (class, indications)

-Class IB Na blocker
-Used for conversion and maintenance when other agents fail

32

How is mexiletine metabolized? What is its half life?

-CYP2D6 and 1A2 (higher doses needed in smokers)
-Variable half life (6-17 hrs)

33

Mexiletine adverse events

-GI
-Dizziness
-Arrhythmias
-Tremor, ataxia

34

Mexiletine contraindications

AV block, cardiogenic shock

35

Flecainide (class, indications, key features)

-Class IC Na blocker
-SVT, AF induced VT
-Pill in pocket conversion to sinus rhythm, paroxysmal AF

36

How is flecainide metabolized? What is its half life?

-CYP2D6
-7-14 hrs in healthy ppl
-19-22 hrs post
-MI-27 hrs w/HF and repeated dosing

37

Flecainide serious adverse events

-AV/BBB, QT prolong
-Dizzy, HA, fatigue
-Dyspnea

38

Flecainide contraindications

RBBB, AV block, cardiogenic shock

39

Propafenone (class, indications, key features)

-Class IC Na blocker
-VT and conversion to sinus rhythm
-Structure similar to propranol

40

How is propafenone metabolized? What is its half life?

-CYP2D6 (extensive 1st pass)
-5 to 8 hours

41

Propafenone serious adverse events

-AV block, Torsades, QT prolonged
-Dizzy and CNS issues

42

Propafenone contraindications

-Bradycardia, AV block, sick sinus
-Electrolyte depletion
-Decompensated HF, hypotension

43

What is unique about esmolol?

Ultra-short acting (effective duration 20-30 mins)

44

What is esmolol used for?

Intraoperative and perioperative tachycardias

45

What are the ADRs of esmolol?

-Hypotension (dose related)
-Diaphoresis
-Nausea
-Bradycardia, bronchospasm, seizure

46

Contraindications of esmolol

-Severe sinus bradycardia
-2nd or 3rd degree AV block
-Cardiogenic shock

47

Propranolol and its uses

-Nonselective B blocker
-Used for acute rate control
-ER form used for long term rate control

48

How is propranolol metabolized and what is unique about its composition?

-CYP2D6 and 1A2 (extensive 1st pass effect)
-Highly protein bound

49

ADRs of propranolol

-Hypotension and bradycardia
-Raynaud's
-Cognitive effects
-Dyslipid and dysglycemia

50

When is propranolol contraindicated?

Severe pulmonary and liver disease

51

What is nadolol and its uses?

-Nonselective B blocker
-3rd or 4th line for rate control
-Other uses: HTN, CAD, variceal hemorrhage, thyroid storm

52

When is nadolol dosing adjusted?

Renal impairment

53

ADRs of nadolol

Same as propranolol
-Hypotension, bradycardia
-Raynaud's
-Cognitive effects
-Dyslipid and dysglycemia

54

Contraindications for nadolol

Severe pulmonary disease

55

What is atenolol and its uses?

-Selective B1 blocker
-Acute VT and maintenance (unlabeled)
-Migraine proph, ETOH withdrawal, HTN, angina, hyperthyroid

56

How is atenolol metabolized?

-Limited hepatic metabolism
-Excreted unchanged in urine/feces

57

Half life of atenolol

6-7 hrs

58

When is dosing of atenolol adjusted?

Renal impairment

59

ADRs of atenolol

*Same as all other selective agents
-Hypotension, bradycardia
-Raynaud's
-Cognitive effects
-Dyslipid and dysglycemia

60

What is metoprolol and its uses?

-Selective B1 blocker
-Acute VT and maintenance (unlabeled)
-Migraine proph, essential tremor, HTN, angina, cardiomyopathy, hyperthyroid

61

How is metoprolol metabolized?

Extensive hepatic (and 1st pass) via CYP2D6

62

ADRs of metoprolol

-Hypotension, bradycardia
-Raynaud’s
-Cognitive dysfunction
-Dyslipid and dysglycemia

63

What is carvedilol and its uses?

-Mixed alpha and beta blocker
-Labeled uses: HTN, angina, post MI LVD and HF
-Unlabeled: maintenance in some AF pts (post MI, stable LVD and HF)

64

Metabolism of carvedilol

-CYP2C9, 2D6, 2C19, 3A4
-Extensive 1st pass hepatic
-Metabolite is 13x more potent

65

ADRs of carvedilol

-Hypotension, bradycardia
-Dizzy, fatigue, weak
-Endocrine and metabolic
-Peripheral edema

66

What is sotalol and its uses?

-Nonselective B blocker and K blocker
-Conversion of sustained VT
-Maintenance after AF converted to NSR
-Maintenance in AF w/HCM (unlabeled)

67

Metabolism of sotalol

-None, excreted unchanged
-90-100% bioavailable
-Decreased absorption w/food (take on empty stomach)

68

Half life of sotalol

12 hours

69

When must sotalol dosing be adjusted?

Renal impairment

70

ADRs of sotalol

-Bradycardia, CP, palpitations
-Fatigue, dizzy, weak

71

What is ibutilide and how is it used?

-K channel blocker
-Used acutely for AF conversion to NSR

72

How is ibutilide metabolized?

Extensive hepatic

73

ADRs of ibutilide

-Post op (Torsades)
-LV dysfunction

74

Ibutilide contraindications

-Long QT
-Low K
-Symptoms more than 48 hrs

75

What is dofetilide and its use?

-K channel blocker
-Acute conversion of AF to NSR (later for maintenance too)

76

What are some caveats of dofetilide?

-Less effective at higher ventricular rates
-Requires corrected QT and electrolytes prior to dosing

77

How does amiodarone work?

-K channel blocker
-ALSO Na, Ca channels and alpha/beta receptors

78

What is amiodarone used for?

-Maintain SR during AF
-Breakthrough VT/VF
-Pulseless VT/VF

79

ADRs of amiodarone

-Pulm toxicity
-Hypotension, HF, cardiogenic shock
-SJS

80

When does K channel blocking effects occur with sotalol?

Doses 160+ mg/day

81

Uses of Verapamil

-AVNRT, SVT, rate control in AF, HTN
-Unlabeled: migraine proph, bipolar, HCM

82

How is verapamil metabolized?

Extensive hepatic

83

ADRs of verapamil

-Gingival hyperplasia
-HA, constipation
-Fatigue, dizzy

84

When does verapamil dosing need to be adjusted?

End stage liver disease

85

Uses of diltiazem?

-PSVT and AF
-Unlabeled: stable narrow complex tachy after adenosine/vagal maneuvers

86

How is diltiazem metabolized?

Extensive 1st pass hepatic

87

ADRs of diltiazem

-Edema, AV block, brady
-HA, dizzy, SOB

88

How is diltiazem dose adjusted?

It is NOT adjusted with renal or hepatic disease

89

What is adenosine?

-Non-VW agent
-Degradation product of ATP

90

Uses of adenosine

-Induces rapid, reversible AV block
-Terminates SVT from AVNRT
-Allows diagnosis of pre-excitation from accessory pathways

91

Half life of adenosine

Less than 10 seconds

92

ADRs of adenosine

-Severe AV block, brady
-Bronchospasm

93

Contraindications of adenosine

-Symptomatic bradycardia
-2nd/3rd AV block
-WPW

94

How does digoxin increase inotropy?

-Inhibits Na/K ATPase pump
-Increases Na entry, K efflux
-Increases Na/Ca exchange to increase contractility

95

Digoxin and maintenance of sinus rhythm

-Inconsistent
-May induce toxicity
-B blockers are safer
-BUT careful use reduces hospitalization

96

Metabolism of digoxin

-Minor hepatic NOT CYP dependent
-Sugar hydrolysis in stomach
-Gut bacteria
-REDUCED rate in HF

97

Half life of digoxin

38 hours