ESMOLOL HYDROCHLORIDE

Clinical safety rating: safe

Animal studies have demonstrated safety

How it works

Selective beta-1 adrenergic receptor antagonist; reduces heart rate, contractility, and blood pressure by blocking catecholamine effects at beta-1 receptors.

What the body does with it

Metabolism	Primarily metabolized by ester hydrolysis in erythrocytes (by esterases) to inactive metabolite ASL-8123 and methanol; minimal hepatic metabolism.
Excretion	Rapid metabolism by red blood cell esterases to inactive acid metabolite (ASL-8123) and methanol; <2% excreted unchanged in urine; primarily renal elimination of metabolites.
Half-life	Terminal elimination half-life: approximately 9 minutes in adults (range 4–13 min); in patients with hepatic impairment: unchanged; in severe renal impairment: prolonged to 12–20 min due to metabolite accumulation. Clinically, rapid offset (within 20–30 min) allows for titration.
Protein binding	55% bound to plasma proteins (primarily albumin).
Volume of Distribution	3.5 L/kg in adults; larger Vd indicates extensive tissue distribution. In patients with heart failure or cirrhosis, Vd may be increased.
Bioavailability	Not orally available due to rapid first-pass hydrolysis; only administered intravenously (IV).
Onset of Action	IV bolus: within 2–5 minutes; IV infusion: 5–10 minutes; sustained hemodynamic effect achieved within 30 minutes of starting infusion.
Duration of Action	Hemodynamic effects persist for 10–20 minutes after discontinuation of IV infusion; complete resolution of beta-blockade within 20–30 minutes. Brief duration allows for rapid titration and reversal.

Classification & Brands

Dosing & administration

Loading dose: 500 mcg/kg IV over 1 minute, followed by maintenance infusion of 50 mcg/kg/min; titrate by 25-50 mcg/kg/min every 5-10 minutes up to 200 mcg/kg/min.

Dosage form	INJECTABLE
Renal impairment	No dose adjustment recommended for GFR >30 mL/min; for GFR <30 mL/min, reduce maintenance infusion by 50% and monitor closely.
Liver impairment	No specific Child-Pugh based modifications; use with caution in severe hepatic impairment due to decreased metabolism, consider lower initial doses.
Pediatric use	Loading dose: 500 mcg/kg IV over 1 minute; maintenance infusion: start at 50 mcg/kg/min, titrate as needed; not approved for hypertension.
Geriatric use	Initiate at lower end of dosing range (25 mcg/kg/min maintenance) and titrate cautiously due to increased sensitivity and potential for bradycardia and hypotension.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

Other drugs that lower heart rate or blood pressure can have additive effects Can cause profound hypotension and bradycardia.

Breastfeeding	Excreted in breast milk in low amounts; M/P ratio is 0.19. Risk of beta-blockade in infant is low due to short half-life. Use with caution; monitor infant for bradycardia and hypotension.
Teratogenic Risk	Pregnancy Category C. Esmolol crosses the placenta and may cause fetal bradycardia, hypotension, and hypoglycemia, especially in the third trimester. Use only if benefit outweighs risk; avoid in first trimester unless essential.
Fetal Monitoring

Warnings & precautions

■ FDA Black Box Warning

No FDA black box warnings.

Side Effect Profile

Common Effects	supraventricular tachycardia
Serious Effects

Absolute Contraindications

["Sinus bradycardia","Sick sinus syndrome","Second- or third-degree atrioventricular block","Cardiogenic shock","Decompensated heart failure","Severe hypotension","Known hypersensitivity to esmolol or beta-blockers","Pulmonary edema","Concomitant use with intra-arterial vasodilators (phentolamine)","Severe asthma/COPD (relative caution)"]

Clinical Precautions

Precautions

["Hypotension (dose-limiting)","Bradycardia","Heart failure exacerbation","Bronchospasm in patients with asthma/COPD","Peripheral hypoperfusion","Diabetic patients may mask hypoglycemia symptoms","Thyrotoxicosis may mask tachycardia","Abrupt withdrawal may cause rebound hypertension/tachycardia","Renal impairment (metabolite accumulation)","Extravasation risk (IV administration)"]

Clinical Tips & Counseling

Drug interactions

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