Table 2.

IV Drugs Used for Tachycardia

DrugCharacteristicsIndication(s)DosingSide EffectsPrecautions or Special Considerations
Intravenous Drugs Used to Treat Supraventricular Tachyarrhythmias
    AdenosineEndogenous 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 pushHypotension, bronchospasm, chest discomfortContraindicated 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, VerapamilNon-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 failureShould 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, Propranololβ-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 failureAvoid in patients with asthma, obstructive airway disease, decompensated heart failure and pre-excited artrial fibrillation or flutter
    ProcainamideSodium 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 metBradycardia, hypotension, torsades de pointesAvoid in patients with QT prolongation and CHF
    AmiodaroneMultichannel 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
    DigoxinCardiac 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 intervalsBradycardiaSlow onset of action and relative low potency renders it less useful for treatment of acute arrhythmias
Intravenous Drugs Used to Treat Ventricular Tachyarrhythmias
    ProcainamideSodium 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 metBradycardia, hypotension, torsades de pointesAvoid in patients with QT prolongation and CHF
    AmiodaroneMultichannel 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
    SotalolPotassium 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 hoursBradycardia, hypotension, torsades de pointesAvoid in patients with QT prolongation and CHF
    LidocaineRelatively 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 infusionSlurred speech, altered consciousness, seizures, bradycardia
    MagnesiumCofactor 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 minutesHypotension, CNS toxicity, respiratory depressionFollow magnesium levels if frequent or prolonged dosing required, particularly in patients with impaired renal function