Antiarrhythmics
Lidocaine
Adult Dosing
- Loading dose = 1-1.5 mg/kg
- Additional boluses of 0.5-0.75 mg/kg q5-10min up to max of 3mg/kg
- If effective start infusion of 2mg/min
Contraindications
- High SA or AV block
Indications
- Treatment of ventricular arrhythmias and ectopy
- Considered 2nd-line to amiodarone for tx of V-fib and pulseless v-tach
Mechanism of Action
- Class Ib
- Binds to fast Na channels in inactive state thereby inhibiting recovery after repolarization
- Acts preferentially on ischemic tissue
- Elevates V-fib threshold
- Suppresses ventricular ectopy
- Little effect on vascular tone, contractility or cardiac output
Adverse Drug Rxns
- CNS
- Abrupt change in MS, drowsiness, confusion, sz
Kinetics
- Onset of action = 45-90s
- Duration of action = 10-20min
Procainamide
Esmolol
Labetalol
Sotalol
Amiodarone
Ibutilide
Diltiazem
Atropine
Adenosine
Digoxin
Isoproterenol
Adult Dosing
2-10mcg/min IV by continuous infusion
Indications
- Refractory torsades
- Refractory symptomatic bradycardia
Mechanism of Action
- Beta agonist
Adverse Drug Rxns
- Dramatic increase in O2 demand
- V-tach (use lowest dose possible)
Kinetics
- Onset of action = 1-5min
- Duration of action = 1-2hr
Magnesium
Adult Dosing
- Loading dose = 1-2gm in 10mL D5W over 1-2min (cardiac arrest)
- Loading dose = 1-4gm in 50-100 D5W over 20-60min (spontaneous circulation)
Contraindications
Indications
- Torsades
- Refractory v-tach/fib (regardless of Mg level)
Mechanism of Action
- Increases vasomotor tone
- Prolongs AV conduction; prolongs refractoriness
Adverse Drug Rxns
- Hypotension (rare)
Kinetics
- Onset of action = Immediate
- Duration of action = 30min
Source
Tintinalli