IV Drugs Used for Tachycardia
Drug Characteristics Indication(s) Dosing Side Effects Precautions or Special Considerations
Intravenous Drugs Used to Treat Supraventricular Tachyarrhythmias
Adenosine Endogenous purine nucleoside; briefly depresses sinus node rate and AV node conduction; vasodilator

  • Stable, narrow-complex regular tachycardias

  • Unstable narrow-complex regular tachycardias while preparations are made for electrical cardioversion

  • Stable, regular, monomorphic, wide complex tachycardia as a therapeutic and diagnostic maneuver

 6 mg IV as a rapid IV push followed by a 20 mL saline flush; repeat if required as 12 mg IV push Hypotension, bronchospasm, chest discomfort Contraindicated in patients with asthma; may precipitate atrial fibrillation, which may be very rapid in patients with WPW;
thus a defibrillator should be readily available; reduce dose in post–cardiac transplant patients, those taking dipyridamole
or carbamazepine and when administered via a central vein
Diltiazem, Verapamil Non-dihydropyridine calcium channel blockers; slow AV node conduction and increase AV node refractoriness; vasodilators, negative
inotropes

  • Stable, narrow-complex tachycardias if rhythm remains uncontrolled or unconverted by adenosine or vagal maneuvers or if SVT
    is recurrent

  • Control ventricular rate in patients with atrial fibrillation or atrial flutter

 Diltiazem: Initial dose 15 to 20 mg (0.25 mg/kg) IV over 2 minutes; additional 20 to 25 mg (0.35 mg/kg) IV in 15 minutes if
needed; 5 to 15 mg/h IV maintenance infusion (titrated to AF heart rate if given for rate control)
Verapamil: Initial dose 2.5 to 5 mg IV given over 2 minutes; may repeat as 5 to 10 mg every 15 to 30 minutes to total dose
of 20 to 30 mg		 Hypotension, bradycardia, precipitation of heart failure Should only be given to patients with narrow-complex tachycardias (regular or irregular). Avoid in patients with heart failure
and pre-excited AF or flutter or rhythms consistent with VT
Atenolol, Esmolol, Metoprolol, Propranolol β-Blockers; reduce effects of circulating catecholamines; reduce heart rate, AV node conduction and blood pressure; negative
inotropes

  • Stable, narrow-complex tachycardias if rhythm remains uncontrolled or unconverted by adenosine or vagal maneuvers or if SVT
    is recurrent

  • Control ventricular rate in patients with atrial fibrillation or atrial flutter

  • Certain forms of polymorphic VT (associated with acute ischemia, familial LQTS, catecholaminergic)

 Atenolol (β1 specific blocker) 5 mg IV over 5 minutes; repeat 5 mg in 10 minutes if arrhythmia persists or recurs
Esmolol (β1 specific blocker with 2- to 9-minute half-life) IV loading dose 500 mcg/kg (0.5 mg/kg) over 1 minute, followed
by an infusion of 50 mcg/kg per minute (0.05 mg/kg per minute); if response is inadequate, infuse second loading bolus of
0.5 mg/kg over 1 minute and increase maintenance infusion to 100 mcg/kg (0.1 mg/kg) per minute; increment; increase in this
manner if required to maximum infusion rate of 300 mcg/kg [0.3 mg/kg] per minute Metoprolol (β1 specific blocker) 5 mg over
1 to 2 minutes repeated as required every 5 minutes to maximum dose of 15 mg Propranolol (nonselective β-blocker) 0.5 to 1
mg over 1 minute, repeated up to a total dose of 0.1 mg/kg if required		 Hypotension, bradycardia, precipitation of heart failure Avoid in patients with asthma, obstructive airway disease, decompensated heart failure and pre-excited artrial fibrillation
or flutter
Procainamide Sodium and potassium channel blocker

  • Pre-excited atrial fibrillation

 20 to 50 mg/min until arrhythmia suppressed, hypotension ensues, or QRS prolonged by 50%, or total cumulative dose of 17 mg/kg;
or 100 mg every 5 minutes until arrhythmia is controlled or other conditions described above are met		 Bradycardia, hypotension, torsades de pointes Avoid in patients with QT prolongation and CHF
Amiodarone Multichannel blocker (sodium, potassium, calcium channel, and noncompetitive α/β-blocker)

  • Stable irregular narrow complex tachycardia (atrial fibrillation)

  • Stable regular narrow-complex tachycardia

  • To control rapid ventricular rate due to accessory pathway conduction in pre-excited atrial arrhythmias

 150 mg given over 10 minutes and repeated if necessary, followed by a 1 mg/min infusion for 6 hours, followed by 0.5 mg/min.
Total dose over 24 hours should not exceed 2.2 g.		 Bradycardia, hypotension, phlebitis
Digoxin Cardiac glycoside with positive inotropic effects; slows AV node conduction by enhancing parasympathetic tone; slow onset
of action

  • Stable, narrow-complex regular tachycardias if rhythm remains uncontrolled or unconverted by adenosine or vagal maneuvers
    or if SVT is recurrent

  • Control ventricular rate in patients with atrial fibrillation or atrial flutter

 8 to 12 mcg/kg total loading dose, half of which is administered initially over 5 minutes, and remaining portion as 25% fractions
at 4- to 8- hour intervals		 Bradycardia Slow onset of action and relative low potency renders it less useful for treatment of acute arrhythmias
Intravenous Drugs Used to Treat Ventricular Tachyarrhythmias
Procainamide Sodium and potassium channel blocker

  • Hemodynamically stable monomorphic VT

 20 to 50 mg/min until arrhythmia suppressed, hypotension ensues, or QRS prolonged by 50%, or total cumulative dose of 17 mg/kg;
or 100 mg every 5 minutes until arrhythmia is controlled or other conditions described above are met		 Bradycardia, hypotension, torsades de pointes Avoid in patients with QT prolongation and CHF
Amiodarone Multichannel blocker (sodium, potassium, calcium channel, α- and noncompetitive β-blocker)

  • Hemodynamically stable monomorphic VT

  • Polymorphic VT with normal QT interval

 150 mg given over 10 minutes and repeated if necessary, followed by a 1 mg/min infusion for 6 hours, followed by 0.5 mg/min.
Total dose over 24 hours should not exceed 2.2 g.		 Bradycardia, hypotension, phlebitis
Sotalol Potassium channel blocker and nonselective β-blocker

  • Hemodynamically stable monomorphic VT

 In clinical studies 1.5 mg/kg infused over 5 minutes; however, US package labeling recommends any dose of the drug should
be infused slowly over a period of 5 hours		 Bradycardia, hypotension, torsades de pointes Avoid in patients with QT prolongation and CHF
Lidocaine Relatively weak sodium channel blocker

  • Hemodynamically stable monomorphic VT

 Initial dose range from 1 to 1.5 mg/kg IV; repeated if required at 0.5 to 0.75 mg/kg IV every 5 to 10 minutes up to maximum
cumulative dose of 3 mg/kg; 1 to 4 mg/min (30 to 50 mcg/kg per minute) maintenance infusion		 Slurred speech, altered consciousness, seizures, bradycardia
Magnesium Cofactor in variety of cell processes including control of sodium and potassium transport

  • Polymorphic VT associated with QT prolongation (torsades de pointes)

 1 to 2 g IV over 15 minutes Hypotension, CNS toxicity, respiratory depression Follow magnesium levels if frequent or prolonged dosing required, particularly in patients with impaired renal function