Esmolol

Indications

Esmolol is used for: Intraoperative Tachycardia/Hypertension, Postoperative/gradual control, Supraventricular Tachycardia, Hypertensive Emergency

Adult Dose

Intravenous Adult: Intraoperative Tachycardia/Hypertension Immediate control Initial bolus: 80 mg (~1 mg/kg) IVP over 30 sec, THEN 0.15-0.3 mg/kg/min IV infusion PRN Postoperative/gradual control Load 0.5 mg/kg IV over 1 min, THEN 0.05 mg/kg/min IV for 4 min If inadequate response in 5 min 2nd loading dose of 0.5 mg/kg/min for 1 min, THEN 0.1 mg/kg/min IV Supraventricular Tachycardia Load: 0.5 mg/kg IV over 1 min, THEN Maintenance: Start 0.05 mg/kg/min IV for 4 min, may increase by 0.05 mg/kg up to 0.2 mg/kg/min If HR/BP not controlled after 5 min, repeat bolus (ie, 500 mcg/kg/min for 1 min), then initiate infusion of 0.1 mg/kg/min IV May administer a 3rd bolus if needed, then a maintenance infusion of 0.15 mg/kg/min IV Higher maintenance doses may be required, up to 0.25-0.3 mg/kg/min Hypertensive Emergency Load 0.25-0.5 mg/kg IVP over 1 min, THEN 0.05-0.1 mg/kg/min IV for 4 min May repeat loading dose or increase infusion up to 0.3 mg/kg/min if necessary

Child Dose

Renal Dose

Renal Impairment Not necessary to supplement dose; not dialyzable

Administration

IV Preparation Solution: 5 g in 500 mL or 2.5 g in 250 mL NS (10 mg/mL) IV Administration Do NOT infuse into small veins or through butterfly catheter Infuse at concentration 10 mg/mL, usually with infusion control device If local reaction develops, change infusion site Do not stop abruptly; possibility of withdrawal effects Intended for short-term use, no longer than 48 hr

Contra Indications

Sinus bradycardia, 2nd and 3rd degree AV block, sick sinus syndrome, cardiogenic shock, overt cardiac failure, pulmonary HTN, untreated phaeochromocytoma, metabolic acidosis, severe asthma. Concomitant admin w/ vasoconstrictive and inotropic agents (e.g. epinephrine, norepinephrine, dopamine), IV Ca channel blockers (e.g. verapamil).

Precautions

Patients w/ inadequate cardiac function, well-compensated heart failure, bronchospastic disease, myasthenia gravis, conduction disorder, peripheral vascular disease. May mask signs and symptoms of hypoglycaemia and hyperthyroidism. Avoid abrupt withdrawal as it may precipate thyroid storm or MI, and may exacerbate angina and ventricular arrhythmias. Renal impairment. Pregnancy and lactation. Monitoring Parameters Monitor BP. Perform continuous ECG, monitor respiratory rate, serum K esp in patients w/ renal impairment.

Pregnancy-Lactation

Interactions

May increase serum digoxin levels. Additive effects w/ catecholamine-depleting drugs (e.g. reserpine). May prolong neuromuscular blockade of succinylcholine. May increase serum levels w/ morphine or warfarin. May decrease hypotensive effects w/ NSAIDs. Potentially Fatal: May lead to fatal cardiac arrest w/ IV Ca channel blockers (e.g. verapamil). Increased risk of reducing cardiac contractility in presence of high systemic vascular resistance w/ vasoconstrictive or inotropic drugs (e.g. dopamine, norepinephrine, epinephrine).

Adverse Effects

Side effects of Esmolol : >10% Hypotension, asymptomatic (25-38%) Hypotension, symptomatic (12%) 1-10% Injection site pain (8%) Nausea (7%) Dizziness (3%) Somnolence (3%) Agitation (2%) Confusion(2%) Headache (2%) Fatigue (1%) Vomiting (1%) <1% Bradycardia Chest pain Anxiety Anorexi Depression Abdominal discomfort Constipation Dry mouth Dyspepsia Taste perversion Bronchospasm Dyspnea Nasal congestion Wheezing

Mechanism of Action

Esmolol is a short-acting cardioselective agent, which competitively blocks beta1-adrenergic receptor while having little effect on the beta2-adrenergic receptors of bronchial and vascular smooth muscle. At high doses, selectivity usually diminishes, and the drug will competitively inhibit beta1- and beta2-adrenergic receptors.