Esmolol

ADMINISTRATION ROUTES:

IV

ALTERNATIVE NAMES:

Breviblock

ICU INDICATIONS:

1. Hypertension
2. Tachydysrhythmia

Note: Esmolol is primarily used where there is concern that beta blockade will not be well tolerated. If an adverse reaction occurs, esmolol has a very short action so the drug will wear off rapidly.

PRESENTATION AND ADMINISTRATION:

IV:

100 mg in 10 mL vial (10 mg/mL)

Use 10 mg/mL solution undiluted for loading dose and infusion

Store at room temperature

Freezing does not adversely affect the product, but exposure to elevated temperatures should be avoided

Protect from light

Esmolol loading dose should be administered by a doctor

Note: Section 29 drug (requires specific notification to Director-General of Health)

DOSAGE:

IV:

Loading dose:

500 mcg/kg over one minute

(e.g. 70kg patient = 3.5 mL of 10 mg/mL)

Maintenance dose:

0-200 mcg/kg/min

Note: due to its high cost and the fact that cheaper alternatives exist, esmolol is rarely given by infusion

DOSAGE IN RENAL FAILURE AND RENAL REPLACEMENT THERAPY:

Dose as in normal renal function

DOSAGE IN PAEDIATRICS:

IV:

Loading dose:

500 mcg/kg over one minute

Maintenance dose:

0-300 mcg/kg/min

CLINICAL PHARMACOLOGY:

Esmolol hydrochloride is a beta1-selective (cardioselective) adrenergic receptor blocking agent with a very short duration of action (elimination half-life is approximately 9 minutes).

CONTRAINDICATIONS:

1. Sinus bradycardia
2. Heart block greater than first degree
3. Cardiogenic shock
4. Overt heart failure

WARNINGS:

Risk of death in unstable patients

Despite the rapid onset and offset of esmolol effects, several cases of death have been reported in complex clinical states where esmolol was being used to control ventricular rate.

Bronchospasm

Because of its relative beta1 selectivity and titratability, esmolol may be used with caution in patients with bronchospastic diseases. However, since beta1 selectivity is not absolute, esmolol should be carefully titrated to obtain the lowest possible effective dose. In the event of bronchospasm, any infusion should be immediately stopped; a beta2 stimulating agent may be administered if conditions warrant but should be used with particular caution as patients already have rapid ventricular rates.

PRECAUTIONS:

General

See WARNINGS

Laboratory Tests:

No tests in addition to routine ICU tests are required

Drug/Laboratory Test Interactions:

None known

IMPORTANT DRUG INTERACTIONS IN ICU:

Caution should be exercised when considering the use of esmolol and verapamil in patients with depressed myocardial function. Fatal cardiac arrests have occurred in patients receiving both drugs.

Esmolol should not be used to control supraventricular tachycardia in the presence of agents which are vasoconstrictive and inotropic such as dopamine, epinephrine, and norepinephrine because of the danger of blocking cardiac contractility when systemic vascular resistance is high.

ADVERSE REACTIONS:

Cardiovascular System:

Symptomatic hypotension, pallor, flushing, bradycardia (heart rate less than 50 beats per minute), chest pain, syncope, pulmonary oedema and heart block

Central Nervous System:

Dizziness, somnolence, confusion, headache, and agitation

Respiratory System:

Bronchospasm, wheezing, and dyspnoea

Gastrointestinal System:

Nausea, vomiting, dyspepsia, constipation, dry mouth, and abdominal discomfort

Skin (infusion site):

Infusion site reactions including inflammation and induration