ESMOLOL 100MG 10ML VIAL 25`S

Esmolol is an ultra-short-acting, cardioselective beta-1 adrenoceptor blocker with a plasma half-life of approximately 9 minutes. It is rapidly metabolised by esterases in red blood cells (not hepatic or renal metabolism), making it unique among beta-blockers.

This ultra-short duration allows precise, titratable heart rate and blood pressure control that can be reversed within minutes of stopping the infusion.

Esmolol is indicated for:

·       Supraventricular tachycardia (SVT), including atrial fibrillation and atrial flutter — for rapid rate control;

·       Sinus tachycardia — when rate control is urgent (e.g., peri-operative tachycardia);

·       Non-compensatory sinus tachycardia; and perioperative hypertension — for short-term control of blood pressure during intubation, extubation, and post-operative periods.

Its ultra-short half-life makes it ideal for intraoperative use and in ICU settings where frequent dose titration is needed, or where rapid reversal of beta-blockade may be required (e.g., in patients with reactive airways, heart failure, or haemodynamic instability).

Esmolol is given exclusively as an intravenous bolus or continuous IV infusion by trained healthcare professionals. It must never be given by intramuscular or subcutaneous injection (tissue necrosis risk), nor as an undiluted IV bolus from the concentrate.

SVT / Rate Control Protocol

•       Loading dose: 500 mcg/kg/min IV infusion over 1 minute.

•       Maintenance infusion: 50–200 mcg/kg/min continuous infusion, titrated every 4 minutes.

•       If response is inadequate, repeat the 500 mcg/kg/min loading dose and increase maintenance by 50 mcg/kg/min increments.

•       Maximum maintenance: 300 mcg/kg/min.

Perioperative Hypertension

Initial bolus: 1,000 mcg/kg over 30 seconds, followed by a 150 mcg/kg/minute continuous infusion, if necessary. Adjust infusion rate up to a maximum dose of 300 mcg/kg/minute as needed to maintain desired heart rate and/or BP.

Dilution for Infusion

For continuous infusion, dilute the concentrate to 10 mg/mL in compatible fluid (0.9% NaCl, 5% glucose, Hartmann's). Prepare infusion solutions in appropriate syringe pumps. Do not administer undiluted or via gravity drip without pump control.

Common Side Effects

•       Hypotension — the most common adverse effect; usually responsive to dose reduction or discontinuation.

•       Bradycardia (heart rate below 50 bpm).

•       Nausea, vomiting.

•       Dizziness, fatigue.

•       Sweating.

Infusion Site Reactions

•       Pain, inflammation, thrombophlebitis at infusion site — more common with peripheral administration of concentrate. Use central venous access when possible.

•       Skin necrosis — with inadvertent extravasation of concentrated esmolol.

Serious Side Effects

•       Severe bronchospasm — in patients with reactive airway disease (asthma, COPD).

•       Severe bradycardia or complete heart block.

•       Cardiac failure — in patients with poor left ventricular function.

Hypotension Management

Hypotension is the dose-limiting adverse effect. It is usually reversed rapidly (within 10–20 minutes) by reducing or stopping the infusion. If hypotension persists, intravenous fluids and vasopressors may be required. Continuous blood pressure monitoring is mandatory during esmolol infusion.

Asthma and COPD

Although esmolol is beta-1 selective, beta-1 selectivity is not absolute, and bronchospasm can occur. Avoid esmolol in patients with asthma or severe COPD. In other cases, have bronchodilator therapy available. Monitor peak flow or oxygen saturation during infusion in at-risk patients.

Rapid Reversibility

The ultra-short half-life means that haemodynamic effects resolve within 20–30 minutes of stopping the infusion — a key advantage in haemodynamically unstable patients. However, this also means careful monitoring is essential throughout infusion, as effects dissipate rapidly if the infusion is interrupted.

Transition to Oral Beta-Blockers

When transitioning from esmolol to oral beta-blockers (e.g., metoprolol, atenolol), administer the first oral dose and then taper esmolol over 1 hour to allow sufficient time for the oral drug to be absorbed.

•       Verapamil or diltiazem (IV) — severe bradycardia, heart block, and cardiac arrest; absolute contraindication to concurrent IV administration.

•       Digoxin — additive bradycardia; monitor heart rate and rhythm closely.

•       Catecholamines / sympathomimetics (adrenaline, dopamine) — antagonised by esmolol; higher doses may be needed; however, unopposed alpha activity with adrenaline can cause reflex bradycardia and hypertension.

•       Antihypertensive agents — additive hypotension.

•       Insulin and oral hypoglycaemics — beta-blockers blunt tachycardia (a warning sign of hypoglycaemia) and prolong hypoglycaemia; monitor glucose in diabetic patients.

•       Neuromuscular blockers (succinylcholine) — esmolol may prolong the duration of neuromuscular blockade.

•       Store below 25 degrees Celsius. Do not freeze.

•       Protect from light.

•       Single-use vial — discard unused solution after use.

•       Prepared infusion solutions are stable for 24 hours at room temperature.

•       Keep out of reach of children.

Esmolol is a hospital-use-only, prescription-only medicine (POM) in Kenya. It is used exclusively in intensive care units, operating theatres, emergency departments, and specialist cardiology settings under continuous monitoring.

It is not suitable for outpatient or community pharmacy prescribing.

Dosing Protocols

•       For SVT rate control: loading 500 mcg/kg over 1 minute, then maintenance 50–200 mcg/kg/min. Re-bolus and up-titrate every 4 minutes until target HR is achieved (typically 60–100 bpm for AF/flutter rate control).

•       For perioperative hypertension: 1.5 mg/kg bolus over 30 seconds (up to 80 mg), then 150–300 mcg/kg/min infusion.

Monitoring Requirements

•       Continuous ECG monitoring throughout infusion.

•       Non-invasive or invasive blood pressure monitoring at a minimum every 5 minutes during loading; continuous once a stable infusion is established.

•       Oxygen saturation monitoring — early detection of bronchospasm.

Infusion Site Care

Esmolol concentrate (250 mg/mL) is caustic — must not be given peripherally undiluted. For peripheral infusion, use a 10 mg/mL concentration maximum. Central venous administration is preferred for prolonged infusions. Inspect the site regularly for signs of extravasation (skin necrosis risk).

Why is esmolol used instead of other beta-blockers in the ICU?

Esmolol's uniquely short half-life (about 9 minutes) means that it can be started, adjusted, and stopped very rapidly with immediate effect on heart rate. If a patient becomes hypotensive or bradycardic, stopping the infusion resolves the problem within 20–30 minutes without the prolonged effect seen with longer-acting beta-blockers like metoprolol or atenolol. This makes it ideal for unstable patients.

Can esmolol cause breathing problems?

Although esmolol preferentially blocks beta-1 receptors (in the heart), it can also weakly block beta-2 receptors in the lungs at higher doses. This can trigger bronchospasm in patients with asthma or severe COPD. It should be avoided in these patients where possible, and bronchodilators should be available whenever esmolol is used.

How quickly does esmolol work?

Esmolol begins to slow the heart rate within 1–2 minutes of starting the infusion. Its full effect at any given dose level is seen within 5 minutes. When the infusion is stopped or reduced, the effect reverses within 10–20 minutes. This rapid on/off effect is what makes esmolol so useful for precise heart rate control in hospital settings.