Chapter 25: Antidysrhythmic Drugs Flashcards
its only use is for ventricular dysrhythmias
lidocaine
very short half-life of less than 10 seconds
adenosine
used for life-threatening dysrhythmias (2)
flecainide, propafenone
will cause a brief episode of asystole after administered
adenosine
disturbances of cardiac rhythm are result of abnormally functioning ____________
cardiac cells
this classification system is based on the electrophysiological effects of drugs on the action potential of the heart
Vaughn Williams Classification System
long-term use leads to corneal microdeposits
amiodarone
can cause a systemic lupus erythematous-like syndrome (contraindicated with SLE)
procainamide
preferentially blocks the beta1-adrenergic receptors that are located primarily in the heart
cardioselective beta blockers
can cause pulmonary toxicity and hepatotoxicity
amiodarone
significant reactions with warfarin and digoxin
amiodarone
requires special training to administer
dofetilide
intrinsic rate of 40-60 bpm
AV node
dosage based on body weight
ibutilide
only administered as fast IV push
adenosine
requires continuous cardiac monitoring for first 3 days of use
dofetilide
slows conduction through the AV node
adenosine
used for atrial and ventricular tachydysrhythmias caused by digitalis toxicity or long QT syndrome
phenytoin
intrinsic rate of <40 bpm
Purkinje fibers
intrinsic rate of 60-100 bpm
SA node
rapid conversion for Afib and Aflutter to normal sinus rhythm
ibutilide
natural pacemaker of the heart
SA node
can cause cinchonism: tinnitus, blurring vision, GI upset
quinidine
contraindicated in heart blocks
beta blockers (II)
indicated for supra and ventricular dysrhythmias
beta blockers (II)
risk for Torsades de Pointes (2)
quinidine (black box warning)
dofetilide
all antidysrhythmic drugs can result in this abnormality
QT prolongation
blocks beta1-adrenergic in heart and beta2-adrenergic receptors in lungs and can exacerbate pre-existing asthma or COPD
noncardioselective beta blockers
black box warning for increased mortality
quinidine
converts paroxysmal supraventricular tachycardia (PSVT) to normal sinus rhythm (NSR)
adenosine
can result in ventricular dysrhythmias
ibutilide
ACLS drug of choice for ventricular dysrhythmias
amiodarone
two most reported side effects of propafenone
dizziness, metallic taste