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DRUG INTERACTIONS
Concomitant use of BREVIBLOC injection with other drugs that can lower blood pressure, reduce myocardial contractility, or interfere with sinus node function or electrical impulse propagation in the myocardium can exaggerate BREVIBLOC's effects on blood pressure, contractility, and impulse propagation. Severe interactions with such drugs can result in, for example, severe hypotension, cardiac failure, severe bradycardia, sinus pause, sinoatrial block, atrioventricular block, and/or cardiac arrest. In addition, with some drugs, beta blockade may precipitate increased withdrawal effects. (See clonidine, guanfacine, and monoxide below.) BREVIBLOC should therefore be used only after careful individual assessment of the risks and expected benefits in patients receiving drugs that can cause these types of pharmacodynamic interactions, including but not limited to:
- Digitalis glycosides: Concomitant administration of digoxin and BREVIBLOC leads to an approximate 10% to 20% increase of digoxin blood levels at some time points. Digoxin does not affect BREVIBLOC pharmacokinetics. Both digoxin and beta blockers slow atrioventricular conduction and decrease the heart rate. Concomitant use increases the risk of bradycardia.
- Anticholinesterases: BREVIBLOC prolonged the duration of succinylcholine-induced neuromuscular blockade and moderately prolonged clinical duration and recovery index of mivacurium.
- Antihypertensive agents clonidine, guanfacine, or moxonidine: Beta blockers also increase the risk of clonidine-, guanfacine-, or moxonidine-withdrawal rebound hypertension. If, during concomitant use of a beta blocker, antihypertensive therapy needs to be interrupted or discontinued, discontinue the beta blocker first, and the discontinuation should be gradual.
- Calcium channel antagonists: In patients with depressed myocardial function, use of BREVIBLOC with cardiodepressant calcium channel antagonists (e.g., verapamil) can lead to fatal cardiac arrests.
- Sympathomimetic drugs: Sympathomimetic drugs having beta-adrenergic agonist activity will counteract effects of BREVIBLOC.
- Vasoconstrictive and positive inotropic agents: Because of the risk of reducing cardiac contractility in presence of high systemic vascular resistance, do not use BREVIBLOC to control tachycardia in patients receiving drugs that are vasoconstrictive and have positive inotropic effects, such as epinephrine, norepinephrine, and dopamine.
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OVERDOSAGE
Signs and Symptoms of Overdose
Overdoses of BREVIBLOC (Esmolol Hydrochloride) can cause cardiac and central nervous system effects. These effects may precipitate severe signs, symptoms, sequelae, and complications (for example, severe cardiac and respiratory failure, including shock and coma), and may be fatal. Continuous monitoring of the patient is required.
- Cardiac effects include bradycardia, atrioventricular block (1st-, 2nd, 3rd degree), junctional rhythms, intraventricular conduction delays, decreased cardiac contractility, hypotension, cardiac failure (including cardiogenic shock), cardiac arrest/asystole, and pulseless electrical activity.
- Central nervous system effects include respiratory depression, seizures, sleep and mood disturbances, fatigue, lethargy, and coma.
- In addition, bronchospasm, mesenteric ischemia, peripheral cyanosis, hyperkalemia, and hypoglycemia (especially in children) may occur.
Treatment Recommendations
Because of its approximately 9-minute elimination half-life, the first step in the management of toxicity should be to discontinue the BREVIBLOC infusion. Then, based on the observed clinical effects, consider the following general measures.
Bradycardia
Consider intravenous administration of atropine or another anticholinergic drug or cardiac pacing.
Cardiac Failure
Consider intravenous administration of a diuretic or digitalis glycoside. In shock resulting from inadequate cardiac contractility, consider intravenous administration of dopamine, dobutamine, isoproterenol, or inamrinone. Glucagon has been reported to be useful.
Symptomatic hypotension
Consider intravenous administration of fluids or vasopressor agents such as dopamine or norepinephrine.
Bronchospasm
Consider intravenous administration of a beta2 stimulating agent or a theophylline derivative.
Dilution Errors
Massive accidental overdoses of BREVIBLOC have resulted from dilution errors. Use of BREVIBLOC PREMIXED Injection and BREVIBLOC DOUBLE STRENGTH PREMIXED Injection may reduce the potential for dilution errors. Some of these overdoses have been fatal while others resulted in permanent disability. Bolus doses in the range of 625 mg to 2.5 g (12.5-50 mg/kg) have been fatal. Patients have recovered completely from overdoses as high as 1.75 g given over one minute or doses of 7.5 g given over one hour for cardiovascular surgery. The patients who survived appear to be those whose circulation could be supported until the effects of BREVIBLOC resolved.
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CONTRAINDICATIONS
BREVIBLOC (Esmolol Hydrochloride) is contraindicated in patients with:
- Severe sinus bradycardia: May precipitate or worsen bradycardia resulting in cardiogenic shock and cardiac arrest [see Warnings and Precautions].
- Heart block greater than first degree: Second- or third-degree atrioventricular block may precipitate or worsen bradycardia resulting in cardiogenic shock and cardiac arrest [see Warnings and Precautions].
- Sick sinus syndrome: May precipitate or worsen bradycardia resulting in cardiogenic shock and cardiac arrest [see Warnings and Precautions].
- Decompensated heart failure: May worsen heart failure.
- Cardiogenic shock: May precipitate further cardiovascular collapse and cause cardiac arrest.
- IV administration of cardiodepressant calcium-channel antagonists (e.g., verapamil) and BREVIBLOC in close proximity (i.e., while cardiac effects from the other are still present); fatal cardiac arrests have occurred in patients receiving BREVIBLOC and intravenous verapamil.
- Pulmonary hypertension: May precipitate cardiorespiratory compromise.
- Hypersensitivity reactions, including anaphylaxis to esmolol or any of the inactive ingredients of the product (cross-sensitivity between beta blockers is possible).
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