Antiarrhythmic drugs Flashcards
Procainamide MOA
Class 1a
- Na+ channel blocker=primary
- K+ channel blocker=secondary
Procainamide effects
Slows conduction velocity and pacemaker rate
Procainamide clinical applications
Atrial and ventricular arrhythmias
Procainamide side effects
- Torsades de pointes in pt’s with renal failure
- Hypotension
- Long term: Reversible lupus-related sx’s
Lidocaine MOA
Class 1b
- Weak Na+ channel blocker
- Minimal effect on normal tissue
Lidocaine Clinical applications
Ventricular arrhythmias (post-MI)
Lidocaine toxicity
Neurologic sx’s: CNS sedation or excitation
Who do we want to reduce Lidocaine dose in?
- HF pt’s
2. Liver dz pt’s
Flecainide MOA
Group 1c
-Strong Na+ channel blocker
Flecainide effects
No change in AP duration
Flecainide Clinical application
Treat supra ventricular arrhythmias (SVT) in pt’s with a NORMAL HEART
Who do we want to avoid giving Flecainide to?
Ischemic heart disease pt’s (post-MI)
Pro-arrhythmic
Class II drugs
Beta-Blockers
Beta-Blockers effects
Prolongation of AP duration
- Slows SA node automaticity
- Slows AV nodal conduction velocity
Beta-Blocker Clinical applications
- Atrial arrhythmias
2. Prevention of recurrent infarction an sudden death
Beta-Blocker toxicity
- Asthma
- AV block
- Acute HF
Class III drug
- Amiodarone
2. Dofetilide
Amiodarone MOA
Blocks K+ channels
Amiodarone effects
- Prolongs QT (repolarization)
2. Prolongs AP= Prolongs effective refractory period!!!
Amiodarone clinical applications
- Serious Ventricular arrhythmias
2. SVT
Amiodarone toxicity
- Thyroid dysfunction: Hyper-hypothyroidsim
- Pulmonary fibrosis
- Optic neuritis
Amiodarone drug interaction
Many, based on CYP metabolism
What is considered the blue/ash man drug? Why? How do you protect against this?
- Drug: Amiodarone
- Photosensitivity: blue/gray skin
- WEAR SUNBLOCK
What drug has to be initiated in the hospital? Why?
Dofetilide
–>Torsades de point toxicity
