ANTIARRHYTHMIC DRUGS Flashcards
Mechanisms of arrhythmias
- Abnormal automaticity
2. Abnormal conduction
Often induced by antiarrhythmics that changes the shape of AP and prolongs the QT interval
Torsades de Pointes
ECG morphology seen in Torsades de Pointes
Polymorphic Ventricular Tachycardia (PVT)
SINGH-VAUGHAN WILLIAMS CLASSIFICATION
Class 1: Na channel blockers
Class 2: Beta blockers
Class 3: K channel blockers
Class 4: Ca channel blockers
MOAs of Class 1: Na channel blockers
1A: prolong AP
1B: shorten AP
1C: No effect
Drugs of Class 1A of Na channel blockers
DQ Parin
D - Disopyramidine
Q - Quinidine
P - Procainamide
Class 1A drug that causes LUPUS-LIKE SYNDROME
Procainamide
Class 1A drug that causes CINCHONISM (headache, vertigo, tinnitus)
Quinidine
Used to reverse drug-induced arrhythmias due to Class 1A overdose
Sodium lactate
Class 1B antiarrhythmic drugs
MTLP
M - Mexiletine
T - Tocainide
L - Lidocaine
P - Phenytoin
DOC of ventricular arrhythmias post-MI
Class 1B antiarrhythmic drugs
Drugs used for digoxin-induced arrhythmias
Class 1B antiarrhythmic drugs
Class 1B antiarrhythmic drug that is also used for NEUROPATHIC PAIN
Mexiletine
Side effect seen in Tocainide use
Agranulocytosis
Class 1B antiarrhythmic drug that is LEAST CARDIOTOXIC and with significant first-pass effect
LIDOCAINE
Class 1B antiarrhythmic drug that causes congenital malformations (Fetal hydantoin syndrome)
Phenytoin
Class 1C antiarrhythmic drug
EFMP
E - Encainide
F - Flecainide
M - Moricizine
P - Propafenone
Most arrhythmogenic among the Class 1 antiarrhythmic drug
Class 1C
Used only for refractory arrhythmia
Class 1C antiarrhythmic drug
Class
Class 2 antiarrhythmic drugs
PAM-E
Propanolol
Atenolol
Metaprolol
Esmolol
Class 2 antiarrhythmic drugs (Beta-blockers) act on:
Phase 4
T or F. AV node is particularly sensitive to blockers
TRUE
PR interval is usually prolonged
Class 2 antiarrhythmic drugs use for POST-MI PROPHYLAXIS AGAINST SUDDEN DEATH
PAM
Propanolol
Atenolol
Metoprolol
Class 2 antiarrhythmic drug used for THYROTOXIC ARRHYTHMIAS
ESMOLOL
Class 3 antiarrhythmic drugs
ASID
A - Amiodarone
S - Sotalol
I - Ibutilide
D - Dofetilide
Class 3 antiarrhythmic drugs act on:
Phase 3
Hallmark of Class 3 antiarrhythmic drug
Prolongation of AP duration
ECG morphology seen in Class 3 antiarrhythmic drug
Increase in QT interval
Most efficacious of all antiarrhythmic drugs
Class 3 antiarrhythmic drug
Has the longest T1/2
Class 3 antiarrhythmic drug that is used for atrial fibrillation treatment and prophylaxis
-IDES
Ibutilide, Dofetilide
Class 3 antiarrhythmic drug that has both a K+ channel block + beta blockade
SOTALOL and AMIODARONE
Amiodarone toxicity
Pulmonary fibrosis Paresthesia Thyroid dysfunction Tremors Skin deposits Corneal deposits
Class 4 antiarrhythmic drugs (Calcium channel blockers)
Non-dihydropyridine CCBs
VD
V - Verapamil
D - Diltiazem
Class 4 antiarrhythmic drugs is used in
SUPRAVENTRICULAR TACHYCARDIA
DOC for PAROXYSMAL SVT
ADENOSINE
*shortest T1/2 of 15 seconds
MOA of POTASSIUM as an antiarrythymic drug
Depresses ectopic pacemaker
ectopiK