Esmolol Hydrochloride Injection

• Type: Ultra–short-acting beta-blocker

• Drug Class: Selective β1-adrenergic receptor blocker

• Form: Sterile solution for intravenous (IV) infusion or bolus

How It Works

• Esmolol blocks β1-receptors in the heart, leading to:

  • Slowed heart rate (negative chronotropic effect)

  • Reduced heart contractility (negative inotropic effect)

  • Decreased conduction through the AV node (negative dromotropic effect)

• These effects help control rapid heart rhythms and reduce myocardial oxygen demand.

• Because it is metabolized rapidly by red blood cell esterases, its effects wear off quickly after stopping infusion (half-life ~9 minutes).

Common Uses

Esmolol injection is often used in hospital settings for acute, short-term control of:

• Supraventricular tachycardia (SVT)

• Atrial fibrillation or flutter with rapid ventricular response

• Intraoperative or postoperative hypertension

• Sinus tachycardia due to stress, surgery, or other causes

• Hypertensive emergencies (when rapid control of heart rate and BP is needed)

Advantages

• Rapid onset and very short duration – ideal for situations where quick titration is needed

• Can be easily discontinued if side effects occur (effect wears off in minutes)

• Provides precise control of heart rate during surgery or critical care

Possible Side Effects

Common:

• Low blood pressure (hypotension)

• Slow heart rate (bradycardia)

• Dizziness

• Fatigue

Serious but Less Common:

• Heart block or asystole (in patients with conduction abnormalities)

• Worsening of heart failure (if left ventricular function is weak)

• Bronchospasm (rare, but possible in patients with asthma at high doses)

Precautions

• Should be given only under close monitoring (continuous ECG, BP)

• Use with caution in patients with:

  • Severe bradycardia

  • Heart block (unless pacemaker is present)

  • Decompensated heart failure

  • Asthma or severe COPD

• Must be tapered or switched to a longer-acting agent if long-term control is needed