Esmolol (Brevibloc®)
| Esmolol |  |
|---|---|
| Brand Name | Brevibloc® |
| Drug Class | β-Blocker (β1-selective) |
| Primary Indication | Acute Rate Control |
| β1 Selectivity | High |
| Intrinsic Sympathomimetic Activity | No |
| Half-Life | ~9 minutes |
| Route | IV only |
| Metabolism | Plasma esterases |
| FDA Approval | 1986 |
Overview
Esmolol is a short-acting, β1-selective adrenergic receptor antagonist used for rapid, titratable heart rate control in acute settings.
Its ultra-short half-life (~9 minutes) allows for precise titration and rapid discontinuation if adverse effects occur.
It is commonly used in ICU and perioperative settings.
Mechanism of Action
Receptor Activity
- Selective β1-adrenergic receptor antagonist
Cardiac Effects
- ↓ Heart rate
- ↓ Myocardial contractility
- ↓ AV nodal conduction
Net Effect
- Reduced cardiac output
- Rate control in tachyarrhythmias
Minimal β2 activity at therapeutic doses.
Indications
- Acute atrial fibrillation with rapid ventricular response
- Supraventricular tachycardia
- Intraoperative or postoperative tachycardia
- Acute hypertension (short-term control)
- Thyroid storm (adjunct therapy)
Used when rapid onset and rapid offset are desired.
Contraindications
Absolute:
- Severe bradycardia
- Second- or third-degree AV block (without pacemaker)
- Cardiogenic shock
- Decompensated heart failure
Relative / Caution:
- Asthma or severe COPD
- Hypotension
- Peripheral vascular disease
Dosing
IV bolus:
- 500 mcg/kg over 1 minute
Continuous infusion:
- 50–200 mcg/kg/min
Titrated based on heart rate and blood pressure.
Effects dissipate within 10–20 minutes after discontinuation.
Pharmacokinetics
Route:
- Intravenous only
Metabolism:
- Rapid hydrolysis by plasma esterases
Half-life:
- ~9 minutes
Elimination:
- Renal excretion of inactive metabolites
Short half-life allows rapid reversal of effect.
Adverse Effects
Common:
- Hypotension
- Bradycardia
Serious:
- AV block
- Acute heart failure exacerbation
- Cardiogenic shock
Rapid offset reduces prolonged toxicity risk.
Drug Interactions
Additive AV nodal suppression:
- Non-DHP Calcium Channel Blockers (verapamil, diltiazem)
- Digoxin
Other antihypertensives:
- Increased hypotension risk
Monitoring
- Continuous cardiac monitoring
- Blood pressure
- Heart rate
Used in monitored settings (ICU, OR, ED).
Clinical Pearls
- Ultra-short acting β1-selective blocker.
- Ideal for unstable or dynamic clinical situations.
- Effects disappear quickly after discontinuation.
- Metabolized by plasma esterases — not dependent on hepatic metabolism.
- Useful in thyroid storm for rapid rate control.
Comparison Within Class
Compared to Metoprolol:
- Much shorter half-life
- IV only
- More titratable
Compared to Propranolol:
- β1-selective
- Less bronchospasm risk
Compared to Sotalol:
- No potassium channel blockade
- Not used for rhythm control