What is the recommended dose of esmolol in mg/kg?

Recommended Dosing of Esmolol

The recommended dose of esmolol is a loading dose of 500 mcg/kg IV over 1 minute, followed by a maintenance infusion of 50-200 mcg/kg/min, titrated to clinical effect. 1

Initial Dosing Strategy

Esmolol is an ultra-short-acting, cardioselective beta-blocker with a rapid onset and short duration of action, making it ideal for situations requiring quick heart rate control with the ability to quickly adjust dosing.

The FDA-approved dosing regimen includes:

• Loading dose: 500 mcg/kg IV administered over 1 minute
• Initial maintenance infusion: 50 mcg/kg/min for 4 minutes
• Titration: Adjust dose based on response:
  • If inadequate response after 5 minutes, give another loading dose of 500 mcg/kg over 1 minute
  • Increase maintenance infusion by 50 mcg/kg/min increments (up to 200 mcg/kg/min) 1

Dosing Considerations by Clinical Scenario

For Supraventricular Tachycardia/Atrial Fibrillation

• Most patients (60-70%) achieve adequate rate control (20% reduction in heart rate or decrease to <100 bpm) at doses of 200 mcg/kg/min or less
• Average effective dose is approximately 100 mcg/kg/min 1
• Onset of action occurs within 2 minutes, with 90% of steady-state beta-blockade within 5 minutes 2

For Hypertensive Emergencies

• Loading dose of 500 mcg/kg IV over 1 minute
• Maintenance infusion of 50-300 mcg/kg/min 3

For Intraoperative/Postoperative Tachycardia and Hypertension

Two options are available:

1. Immediate control: 1 mg/kg as bolus over 30 seconds, followed by 150 mcg/kg/min
2. Gradual control: 500 mcg/kg as bolus over 1 minute, followed by 50 mcg/kg/min 1

Maximum Recommended Doses

• For tachycardia treatment: Maximum 200 mcg/kg/min (higher doses provide minimal additional heart rate reduction with increased adverse effects)
• For hypertension treatment: Up to 300 mcg/kg/min may be required
• Safety of doses above 300 mcg/kg/min has not been studied 1

Important Clinical Considerations

Pharmacokinetics

• Extremely short elimination half-life (mean: 9 minutes; range: 4-16 minutes)
• Alpha-distribution half-life approximately 2 minutes
• Full recovery from beta-blockade occurs 18-30 minutes after stopping infusion 2
• Metabolized by red blood cell cytosol esterases, independent of renal or hepatic function 2

Monitoring

• Continuous heart rate and blood pressure monitoring is essential during administration
• Hypotension is the most common adverse effect (incidence 0-50%), especially with:
  • Doses exceeding 150 mcg/kg/min
  • Patients with low baseline blood pressure 2
  • Rapid administration of loading dose

Cautions

• Hypotension can be managed by decreasing the dose or discontinuing the infusion
• Symptoms generally resolve within 30 minutes after discontinuation 2
• Use with caution in patients with bronchial asthma, bradycardia, or heart failure 3

Population-Specific Considerations

In some populations, lower doses may be required:

• Chinese patients may require lower maintenance doses (average 73 mcg/kg/min) 4
• Consider starting at lower doses (100-150 mcg/kg/min) in elderly patients or those with lower blood pressure 4

Esmolol's ultra-short duration of action makes it particularly valuable in critical care settings where rapid titration and quick offset of action are needed for patient safety.