Drug Information: Esmolol
Esmolol is a beta-adrenergic blocking agent used primarily for the rapid control of ventricular rate in patients with supraventricular tachycardia, including atrial fibrillation and atrial flutter. Its ultra-short duration of action makes it particularly useful in situations where rapid onset and offset of beta-blockade are desired, allowing for close titration of the drug’s effects. Esmolol is administered intravenously and is rapidly metabolized by red blood cell esterases, resulting in a short half-life.
Category
Antihypertensive
Mechanism of Action
Esmolol is a selective beta-1 adrenergic receptor blocker. Beta-1 receptors are primarily located in the heart. By blocking these receptors, esmolol decreases heart rate, contractility, and conduction velocity, particularly at the sinoatrial (SA) and atrioventricular (AV) nodes. This results in a reduced cardiac output and blood pressure. Unlike some other beta-blockers, esmolol has minimal intrinsic sympathomimetic activity (ISA) and membrane-stabilizing activity (MSA). Its rapid metabolism by red blood cell esterases leads to its very short half-life (approximately 9 minutes), allowing for quick adjustments in dosage and a rapid return to baseline when the drug is discontinued. This makes it ideal for situations requiring precise control of heart rate and blood pressure.
Clinical Uses
Esmolol’s primary clinical use is for the rapid control of heart rate in supraventricular tachyarrhythmias, such as atrial fibrillation and atrial flutter. It is also frequently employed during and after surgery to manage perioperative hypertension and tachycardia. Other applications include the treatment of noncompensatory sinus tachycardia where, in the physician’s judgment the rapid heart rate requires specific intervention, treatment of tachycardias and hypertension occuring in the perioperative period and treatment of intraoperative and postoperative tachycardia and/or hypertension.
Dosage
Adult Dosage: Typically administered intravenously. A common regimen involves a loading dose of 500 mcg/kg/min over 1 minute, followed by a maintenance infusion of 50 mcg/kg/min. The maintenance infusion can be titrated upwards every 4 minutes as needed, up to a maximum of 200 mcg/kg/min.
Pediatric Dosage: Dosage should be individualized based on the patient’s clinical condition and response. Typically, a loading dose of 500 mcg/kg IV over 1 minute, followed by a maintenance infusion of 50 mcg/kg/min. Can titrate the maintenance infusion to a max of 300mcg/kg/min, adjusting as needed
Indications
* Supraventricular tachycardia (SVT)
* Atrial fibrillation with rapid ventricular response
* Atrial flutter with rapid ventricular response
* Perioperative hypertension and tachycardia
* Noncompensatory sinus tachycardia
Contraindications
* Severe bradycardia (heart rate less than 50 bpm)
* Second- or third-degree heart block (unless a functioning pacemaker is present)
* Cardiogenic shock
* Overt heart failure
* Hypotension (systolic blood pressure less than 100 mmHg)
* Known hypersensitivity to esmolol or its components
* Sick sinus syndrome (unless a functioning pacemaker is present)
* Pulmonary hypertension
FAQ
Q: What is Esmolol used for?
A: Esmolol is primarily used to rapidly control heart rate in supraventricular tachycardias, as well as to manage hypertension and tachycardia during and after surgery.
Q: How is Esmolol administered?
A: Esmolol is administered intravenously, typically with a loading dose followed by a continuous infusion.
Q: What are the common side effects of Esmolol?
A: Common side effects include hypotension, bradycardia, nausea, and dizziness.
Q: How quickly does Esmolol work?
A: Esmolol has a rapid onset of action, with effects typically seen within minutes of administration.
Q: How long does Esmolol’s effect last?
A: Due to its short half-life, the effects of Esmolol are relatively short-lived, typically lasting only a few minutes after discontinuation.
Q: Can Esmolol be used in patients with asthma?
A: Esmolol should be used with caution in patients with asthma or other reactive airway diseases, as it can cause bronchospasm. Selective beta-1 blockers are preferred when beta-blockade is necessary in asthmatics.
Q: What should I do if my blood pressure gets too low while taking Esmolol?
A: If your blood pressure drops too low, the infusion rate should be decreased or discontinued. Supportive measures, such as fluid administration, may be necessary.
Q: Does Esmolol interact with other medications?
A: Yes, Esmolol can interact with other medications, including other beta-blockers, calcium channel blockers, and digoxin. Consult with a healthcare professional about potential drug interactions.
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