Antiarrhythmics Flashcards
Quinidine
CLASS: Class IA, Na+ Channel Blocker
(Fast channel blockers
MOA:Suppress Ventricular and Supraventricular arrhythmias
Forms active metabolites via
CYP3A4 Inhibits CYP2D6, CYP3A4, and P-glycoprotein
USES:A-fib
Suppress ventricular and
supraventricular arrhythmias
AE:Torsades de pointes
SA & AV block/asystole
Nausea, vomiting, diarrhea
Thrombocytopenic purpura
Hemolytic anemia
Toxic dose!V-tach (worsened by hyperkalemia)
Cinchonism!blurry vision, tinnitus, HA, psychosis
Mixed α-block and antimuscarinic properties
↑digoxin by ↓renal clearance
Procainamid
CLASS: Class IA, Na+ Channel Blocker
(Fast channel blockers
MOA: MOA:Suppress Ventricular and Supraventricular arrhythmias
IV Metabolized by cyp2D6
Partly acetylated to N Acetylprocainamide
(NAPA) prolong duration of AP
(class II
Slow Phase 0 & decrease slope of phase 4
USES:DOC for mgmt. of stable preexcited A-fib
Suppress ventricular and
supraventricular arrhythmias
Reserved for life-threatening
arrhythmias d/t pro arrhythmic
effect
AE:Reversible lupus like syndrome Toxic dose!asystole, v-tach CNS!depression, hallucination, psychosis Weak anticholinergic effect Hypotension
Disopyramide
CLASS: Class IA, Na+ Channel Blocker
(Fast channel blockers
MOA: MOA:Suppress Ventricular and Supraventricular arrhythmias
Slow Phase 0 & decrease slope of phase 4
USES:Suppress ventricular and supraventricular arrhythmias
A-fib
AE:Pronounce (-)ve inotropic effect
Severe antimuscarinic effects (dry mouth, urinary retention,
blurry vision, constipation etc.)
Can induce hypotension and cardiac failure w/o pre-existing myocardial dysfunction
Lidocaine
CLASS: class 1B Na+ Channel Blocker (Fast channel blockers)
MOA:Suppress Ventricular arrhythmias only
IV only(extensive first pass metabolism
USES:DOC for termination of V-tach and prevention of Vfib
after cardioversion
Txt of digitalis-induced arrhythmia
AE:Wide toxic therapeutic ratio CNS!drowsiness, slurred speech, agitation etc. Little effect on LV fxn NO (-) ve inotropic effect Cardiac arrhythmias Toxic dose!convulsions, coma
Mexeletine
CLASS: class 1B Na+ Channel Blocker (Fast channel blockers)
MOA:Suppress Ventricular arrhythmias only
USES:Mgmt. of severe ventricular arrhythmias
AE:Mainly CNS and GI
Flecainide
CLASS: Class 1C Na+ Channel Blocker
(Fast channel blockers)
MOA:Suppress Ventricular and Supraventricular arrhythmias
Markedly depress Phase 0
USES:Symptomatic ventricular arrhythmias, PVC, or V-tach
Life threatening ventricular arrhythmia & prevent
paroxysmal A-fib
Suppression of atrial arrhythmias in a structurally
normal heart
AE:(-)ve inotropic effects!worsens CHF
CNS: dizziness, blurry vision, HAGi: nausea, vomiting, diarrhea
Associated with potential for fatal ventricular arrhythmias&
V-tach in persons with structural heart disease
Contraindicated in pts w/ post-MI PVC
Propafenone
CLASS: Class 1C Na+ Channel Blocker
(Fast channel blockers)
MOA:Suppress Ventricular and Supraventricular arrhythmias
Markedly depress Phase 0
USES:Life threatening ventricular arrhythmia & maintain sinus rhythm in pts w/ symptomatic A-fib
Suppression of atrial arrhythmias in a structurally
normal heart
AE:(-)ve inotropic effects!worsens CHF
CNS: dizziness, blurry vision, HA
Gi: nausea, vomiting, diarrhea
β-blocker activity!bronchospasm!worsens CHF etc.
Associated with potential for fatal ventricular arrhythmias&
V-tach in persons with structural heart disease
Propranolol
CLASS:B-Blockers
MOA:Suppress Ventricular and Supraventricular arrhythmias
Reduce HR and contractility
USES:Reduce incidence of sudden arrhythmic death after MI
Control supraventricular tachycardia (a-fib, a-flutter, AV nodal re-entrant tachycardia)
V-tach (Catecholamine induced arrhythmias, digoxin toxicity
AE:Bradycardia
Hypotension
CNS effects
Metoprolol
CLASS:B-Blockers
MOA:Suppress Ventricular and Supraventricular arrhythmias
Reduce HR and contractility
USES:Reduce incidence of sudden arrhythmic death after MI
Control supraventricular tachycardia (a-fib, a-flutter, AV nodal re-entrant tachycardia)
V-tach (Catecholamine induced arrhythmias, digoxin toxicity
AE:Bradycardia
Hypotension
CNS effects
Esmolol
CLASS:B-Blockers,Short acting β1 Selective antagonist
MOA:Suppress Ventricular and Supraventricular arrhythmias
Reduce HR and contractility
USES:Acute arrhythmias occurring during surgery or
emergencies
AE: Contraindicated in acute CHF, severe bradycardia or heart block and severe hyperactive airway disease
Amlodarone
CLASS: Class III, K Channel Blocker,
MOA: Suppress Ventricular and Supraventricular arrhythmias
Block repolarizing K+ channels Prolong AP (QT interval) w/o altering Phase 0 or resting membrane potential Prolong effective refractory period
USES:Most common antiarrhythmic
Mgmt. of ventricular & supraventricular arrhythmias
DOC for acute VT refractory to cardioversion shock
Low dose!maintain normal sinus rhythm in pts w/
A-fib
AE:Most common antiarrhythmic
Mgmt. of ventricular & supraventricular arrhythmias
DOC for acute VT refractory to cardioversion shock
Low dose!maintain normal sinus rhythm in pts w/
A-fib
Sotalol
CLASS: Class III, K Channel Blocker,
MOA: Suppress Ventricular and Supraventricular arrhythmias
Block repolarizing K+ channels Prolong AP (QT interval) w/o altering Phase 0 or resting membrane potential Prolong effective refractory period
USES:Life threatening ventricular arrhythmias
Maintain sinus rhythm in pts w. A-fib, A-flutter
DO NOT use for asymptomatic arrhythmias d/t proarrhythmic
effects
AE:Lowest rate of acute/long term AE
Torsades de pointe (prolonged QT interval)
Cation in pts. with renal impairment
Dofetilide
CLASS: Class III, K Channel Blocker,
MOA: Suppress Ventricular and Supraventricular arrhythmias
Block repolarizing K+ channels Prolong AP (QT interval) w/o altering Phase 0 or resting membrane potential Prolong effective refractory period
USES: Conversion of a-fib/a-flutter to normal sinus rhythm
Maintain sinus rhythm in pts w. chronic A-fib, Aflutter
of longer than 1 week
AE:HA, chest pain, dizziness, V-tach
Torsades de pointes (prolongs QT interval
Verapamil
CLASS: Class IV,Ca2+ Channel Blockers
Suppress Supraventricular
arrhythmias
MOA:Block L-type Ca2+ channels
↓inward Ca2+ current! ↓rate of phase 0 depolarization
Slows conduction in tissues dependent on Ca2+ current (AV node
and SA node)
Major effects on both vascular and cardiac smooth muscle
USES:More effective against atrial than VT arrhythmias
SV-tach
↓ventricular rate in A-fib and A-flutter
HTN & angina
AE:(-) ve inotropes
Transient ↓BP
CNS effects!HA, fatigue, dizziness
GI!constipation, nausea
Verapamil!↑concentration of digoxin, Dofetilide, simvastatin & lovastatin
Diltiazem
CLASS: Class IV,Ca2+ Channel Blockers
Suppress Supraventricular
arrhythmias
MOA:Block L-type Ca2+ channels
↓inward Ca2+ current! ↓rate of phase 0 depolarization
Slows conduction in tissues dependent on Ca2+ current (AV node
and SA node)
Major effects on both vascular and cardiac smooth muscle
USES:More effective against atrial than VT arrhythmias
SV-tach
↓ventricular rate in A-fib and A-flutter
HTN & angina
AE:(-) ve inotropes
Transient ↓BP
CNS effects!HA, fatigue, dizziness
GI!constipation, nausea
Verapamil!↑concentration of digoxin, Dofetilide, simvastatin & lovastatin
