Anti-arrythmics Flashcards
Class 1’s
1A - Quinidine, procainemide
1B - Lidocaine
1C- Flecainide
Class 2’s
Propranolol, esmolol
Class 3’s
Amiodorone, Sotolol
Dofetalide, Ibutilide
Class 4’s
Verapamil, diltiazem
Local anesthetics - MoA
Binds to, inhibits, and releases from Na+ Channels a different rates
Class 1A (Procainamide, quinidine) - specific MoA
Intermediate binding
Drops conductivity, automaticity
Increases refractory, threshold
Increases QRS, QT
nothing to PR
Quinidine - adverse effects
anticholinergic, alpha receptor antagonist
Use with digitalis, beta block, or calcium channel block
Quinidine - spectrum
Atrial fibrillation and flutter
Procainamide - spectrum
supraventricular and ventricular arrhythmias
WPW with atrial fib
Class 1A- adverse effects
hypotension, torsades de pointes (incr. QT)
Lupus like syndrome with procainamide
Class 1B (lidocaine) - specific MoA
Fast binding,
No change in phase 0
incr. threshold
decr. phase 0 conduction in fast beating heart
incr. QRS in fast beating or ischemic heart
Lidocaine - spectrum
only ventricular tachycardia and fibrillation NOT atrial
Lidocaine - adverse effects
Dizziness, drowsiness
Less QT effect
Class 1C- Flecainide and propafenone - specific MoA
Very slow binding
Subs. decr. phase 0 and automaticity
incr. APD (K+) and refractory
Incr. PR, QRS, and QT
Flecainide - spectrum
supraventriculars, PVCs, ventricular tachy, and WPW
Flecainide - adverse effects
Proarrythmia and sudden death
heart failure
Class 2 (propranolol, esmolol) - MoA
Beta-blockers
Class 2 - specific MoA
incr action potential duration and refractory period in AV node
decr slope of phase 4 depolar
Incr. PR
Decr. HR
Propranolol - spectrum
sinus and other tachys
convert reentry loops through AV node
Propranolol - adverse effects
bronchospasm, hypotension
AV block or ventri. failure maybe produce detrimental results
Class 3 (amiodorone, dronedarone, sotalol, ibutilide, dofetalide) - MoA
Potassium channel blockers
Class 3 - specific MoA
incr refractory, APD, threshold
decr. phase 0, phase 4, speed of AV conduction
Incr. PR, QRS, QT,
Decr HR
Amiodorone -oral/IV - spectrum
most arrythmias
Ventr. tachy and V fib
Heart failure arrythmias
Amiodorone - adverse effects
pulmonary fibrosis hepatic injury increase LDL cholesterol Thyroid disease photosensitivity corneal lesions
Dronedarone -oral
No iodine like amiodorone
No thyroid disease risk
Torsades risk
No for heart failure
Sotolol -oral
Ventricular and atrial tachycardias
Incr QT
Decr HR
Sotolol- adverse effects
Proarrhythmia
Fatigue
Insomnia
Ibutilide -IV
Pure potassium current blocker
Atrial fib and flutter
Incr APD, QT (torsades risk)
Dofetilide - oral
Pure potassium current blocker
Atrial fib and flutter
Incr APD, refractory, QT
Class IV (Verapamil/Diltiazem)- MoA
Calcium channel blockers
Class IV - specific MoA
decr. phase 0 slope (AV, calcium current)
decr. phase 4
incr. refractory period in AV node
Incr. PR
Class IV - spectrum
control ventricles during atrial tachy.
convert supraventricular tachy
DAD derived ventricular tachycardia
Calcium channel blockers
Partial AV block caution
Beta blocker on board can lead to asystole
Caution with hypotension
Adenosine (IV) - MOA
binds alpha1 receptors and activates K+ currents in AV and SA node
decr. APD and hyperpolarization
decr HR
Blocks/slows AV conduction
Adenosine - spectrum
convert re-entrant supraventricular arrhythmias
Digioxin
enhances vagal activity (incr. K currents, decr. Ca, incr. refractory)
Slows AV conduction and slows HR
Atrial fib and flutter
Atropine
muscarinic antagonist
blocks vagal activity to speed av conduction and incr HR
Magnesium
Treats torsades (long QT)
