Anti-arrhythmic Flashcards
What is the MOA for a class 1 anti-arrhythmic drug
Sodium channel blocker
What class is Quinidine (Quinidex)
Class 1a
What are the indications for Quinidine (quinidex)
A-flutter, A-fib, AV and ventricular arrhythmias
What are the side-effects of Quinidine (Quinidex)
Potentially pro-arrhythmic, nausea, vomiting, diarrhea. Cinchonism
What are the symptoms of cinchonism
Visual changes, altered sensorium, N/V, psychosis
What rhythm may result from Quinidine use
Torsade de Pointes
What class is Mexiletine (Mexitil)
Class 1b
What is the MOA of Mexiletine (mexitil)
Blocks open sodium channels thereby shortening phase 3 repolarization
What is the most common side effect of all anti-rhythmic drugs
a different dysrhythmia
what class is Flecainide (Tambocor)
Class 1c
What is the indication for flecainide (Tambocor)
supraventricular tachycardia dysrhythmias, including Wolff-Park-White syndrome
What class is atenolol (Tenormin)
Class 2
What is the MOA for atenolol (tenormin)
Beta 1 blockade reduces sympathetic effects on myocardium. Reduced phase 4 depolarization and decreased automaticity in the SA node, AV node and the Purkinje fibers
What are the side effects for atenolol
nightmares, impotency, depression, bradycardia, hypotension
What class is amiodarone (cordarone)
Class 3
What is the MOA of amiodarone (Cordarone)
Potassium channel blockade. Prolongs phase 3
What are the side-effects of amiodarone (Cordarone)
Dizziness and light headedness. Pulmonary fibrosis possible. Blue-gray coloring of skin can occur as a result of iodine deposition
What are the indications of Amiodarone (cordarone)
ventricular arrhythmias
What class is verapamil (Isoptin, Calan)
Class 4 (calcium channel blocker)
What are the indications for verapamil (and other Ca channel blockers
atrial dysrhythmias, like A-fib
What is the MOA of Verapamil
Calcium channel blockade causes a slowing of phase 4 depolarization, resulting in slowed AV conduction.
What is adenosine used for
Adenosine is recommended as the initial drug of choice for PSVT (paroxysmal supraventricular tachycardias)
What is the MOA of adenosine
acts directly on sinus pacemaker cells and vagal nerve terminals. right at that SA node! Within seconds decreases rate and force of contraction
How is adenosine administered
Available for IV administration only
How long does the action of adenosine last
15 seconds
What are the side effects of adenosine
Low toxicity but often causes transient hypotension and chest pain
What class is atropine
anti-arrythmic
what are the indications of atropine
to treat bradycardia
what is the MOA of atropine
Anticholinergic agent - Atropine is a competitive inhibitor of the muscarinic acetylcholine receptors thus it can be thought of as a parasympatholytic
What are the side effects of atropine
dry mouth, dry eyes, dilated pupils, blurred vision
How is atropine delivered
IV, PO, and endotracheal tube
When is it appropriate to use atropine
In an emergency setting when there is life threading bradycardia and hypotension
What is atropine an antidote for
organophosphate poisoning from pesticides or nerve gas
What is the antidote to atropine
physostigmine
What are signs of atropine toxicity
decreased secretions; flushed, dry, warm skin, visual changes and delirium with hallucinations.
“Dry as a bone, red as a beet, hot as a hare, blind as a bat, mad as a hatter.”
What drug class is Digoxin
Cardiac glycoside
What is the difference between digoxin and digitoxin
Compared to digoxin, digitoxin has longer half life (~ 7 days), is absorbed more readily, is more highly protein bound and is more extensively metabolized before excretion.
What effect does digoxin have on the heart
It slows the rate yet increases the contractility by inhibiting the Na/K ATPase pump
What are the indications of digoxin
CHF, failing other heart drugs
What are the signs of digitalis intoxication
Halos around light, flickers, dots, blurred vision, N/V, diarrhea, bradycardia, heart block,
What increases the risk of digitalis intoxication
low potassium esp in those on potassium wasting diuretic
What is the antidote to digitalis intoxication
administering specific immune antibodies, known as Digoxin immune Fabs
