-
Disopyramide
- - Class IA Sodium Channel Blocker
- - Intermediate kinetics and increases action potential duration
- - caution with renal dysfunction
- Side effects:
- - Cause Long QT (potassium channel blocker like)
- - anti parasympathetic (anticholinergic)
- - negative inotrope
- Uses:
- - Supraventricular tachycardia, VT, AF
- - proarrythmic
-
Procainamide
- - Class IA Sodium Channel Blocker
- - Intermediate kinetics and increases action potential duration
- - caution with renal dysfunction
- - Cause Long QT (potassium channel blocker like)
- Uses:
- - SVT, AF, VT
- Side effects:
- - torsades, lupus like syndrome
-
Lidocaine
- - IV administration
- - Class IB Na channel blocker
- - preferentially affect ventricle due to affinity for open channels
- - caution in hepatic dysfunction
- - Reduce action potential duration
- Uses: VT, Digoxin induced VT and torsades/long QT
- Side effects: neurological dizziness confusion etc., sinus slowing
-
Mexilitine
- - Oral
- - Class IB Na channel blocker
- - preferentially affect ventricle due to affinity for open channels
- - caution in hepatic dysfunction
- - Reduce action potential duration
- Uses: VT, Digoxin induced VT and torsades/long QT
- Side effects: neurological dizziness confusion etc., sinus slowing
-
Flecainide, Propafenone
- Class IC Na Channel Blocker
- - severe blocking effect
- - widens QRS
- Uses: AF, refactory SVT
- Side effects: parasthesia (tingling) diplopia (double vision) chest pain
- - Very proarrhythmic ((can cause 1:1 AV conduction if not used with AVnode blockers))
-
carvedilol, propanolol, esmolol, labetolol
- carvedilol (PO),propanolol (PO),esmolol (IV),labetolol (IV/PO)
- Class II beta- adrenergic blockers
- o Slow sinus rate, prolong AV‐node conduction and refractoriness,inhibit automaticity
- oUses: SVTs, VT‐due to MI, mortality benefit in MI/CHF patients
- o Side effects: bradycardia, fatigue, dizziness, hypotension, depression
-
amiodarone, sotalol, dofetilide, ibutilide, dronedarone
- Class III: Potassium Channel Blockers
- amiodarone (IV/PO), sotalol (PO) ,dofetilide (PO), ibutilide (IV), dronedarone (PO)
- o Prolong refractoriness (i.e. phase III) by blocking K+ channels
- o Uses: Atrial fibrillation, VT
- -Sotalol- greater effect at slower heart rates
- - may be better at preventing arrhythmias than stopping them
- o Side effects: LongQT-->Torsades de Pointes
- Note: amiodarone: most effective drug for preventing recurrent AF and for treating VT/VF, but has adverse effects in almost every organ system (see lecture for all side effects), also decreases automaticity
-
diltiazem, verapamil
- Class IV Ca channel blockers
- diltiazem (IV/PO), verapamil (PO)
- Block L-type Ca channels (phases 4 & 0)
- o MAJOR: Prolonged AV node conduction and refractoriness
- oMinor: sinus node slowing, reduce automaticity
- Uses: rate control for AF/Atrial Flutter, treatment of SVT
- o Side effects: bradycardia, CHF, fatigue, dizziness, edema, gingivalhyperplasia
-
Digoxin
- o Increase vagal tone via CNS effect--> binds to Na pumps in neuronal plasma membranes and inhibits sympathetic outflow
- o Decreases AV nodal conduction and increases AV refactoriness
- o Also blocks Na‐K ATPase--> increases intracellular Ca++-->+ inotropy
- o Uses: AF (CHF patients)
- o Side effects: narrow therapeutic window, AV block, bradycardia,visual disturbances (i.e. seeing yellow/green)
-
Adenosine
- - binds to adenosine A1 receptor
- o Slows SA and decreases AV nodal conduction; also activated outward K+ channel in atrium, shortening atrial refractoriness
- o Uses: diagnosis and treatment of SVTs
- o Side effects: AV block/asystole, flushing, headache, bronchospasm (not for asthmatics)
-
Atropine
- o Blocks the action of acetylcholine at parasympathetic sites
- o Uses: symptomatic sinus bradycardia or AV node block
- o Side effects: tachycardia, glaucoma, urinary retention, dilated pupils
|
|
