Brevibloc Injection

Brevibloc Premixed (esmolol hydrochloride) Injection is a beta-blocker indicated for the rapid control of ventricular rate in patients with atrial fibrillation, or atrial flutter in perioperative, postoperative, or other emergent circumstances.

• Brevibloc is also indicated in noncompensatory sinus tachycardia where the rapid heart rate requires specific intervention. Brevibloc is available in generic form.
• Supraventricular Tachycardia Or Noncompensatory Sinus Tachycardia Brevibloc (Esmolol Hydrochloride) injection is indicated for the rapid control of ventricular rate in patients with atrial fibrillation or atrial flutter in perioperative, postoperative, or other emergent circumstances where short term control of ventricular rate with a short-acting agent is desirable.
• Brevibloc injection is also indicated in noncompensatory sinus tachycardia where, in the physician's judgment, the rapid heart rate requires specific intervention. Brevibloc injection is intended for short-term use.
• Intraoperative And Postoperative Tachycardia And/Or Hypertension Brevibloc (Esmolol Hydrochloride) injection is indicated for the short-term treatment of tachycardia and hypertension that occur during induction and tracheal intubation, during surgery, on emergence from anesthesia and in the postoperative period, when in the physician's judgment such specific intervention is considered indicated. Use of Brevibloc injection to prevent such events is not recommended.

Common side effects of Brevibloc include:

• low blood pressure (hypotension).

Infrequent side effects of Brevibloc include:

• anxiety,
• drowsiness,
• nausea,
• vomiting,
• headache,
• nervousness, and
• redness of the face and neck.

Dosing for the Treatment of Supraventricular Tachycardia or Noncompensatory Sinus Tachycardia

Brevibloc injection is administered by continuous intravenous infusion with or without a loading dose. Additional loading doses and/or titration of the maintenance infusion (step-wise dosing) may be necessary based on desired ventricular response.

Table 1 : Step-Wise Dosing

In the absence of loading doses, continuous infusion of a single concentration of esmolol reaches pharmacokinetic and pharmacodynamic steady-state in about 30 minutes.

The effective maintenance dose for continuous and step-wise dosing is 50 to 200 mcg per kg per minute, although doses as low as 25 mcg per kg per minute have been adequate. Dosages greater than 200 mcg per kg per minute provide little added heart rate lowering effect, and the rate of adverse reactions increases.

Maintenance infusions may be continued for up to 48 hours.

Intraoperative and Postoperative Tachycardia and Hypertension

In this setting it is not always advisable to slowly titrate to a therapeutic effect. Therefore two dosing options are presented: immediate control and gradual control.

Immediate Control

• Administer 1 mg per kg as a bolus dose over 30 seconds followed by an infusion of 150 mcg per kg per min if necessary.
• Adjust the infusion rate as required to maintain desired heart rate and blood pressure. Refer to Maximum Recommended Doses below

Gradual Control

• Administer 500 mcg per kg as a bolus dose over 1 minute followed by a maintenance infusion of 50 mcg per kg per min for 4 minutes.
• Depending on the response obtained, continue dosing as outlined for supraventricular tachycardia. Refer to Maximum Recommended Doses below.

Maximum Recommended Doses

• For the treatment of tachycardia, maintenance infusion dosages greater than 200 mcg per kg per min are not recommended; dosages greater than 200 mcg per kg per min provide little additional heart rate-lowering effect, and the rate of adverse reactions increases.
• For the treatment of hypertension, higher maintenance infusion dosages (250-300 mcg per kg per min) may be required. The safety of doses above 300 mcg per kg per minute has not been studied.

Transition from Brevibloc Injection Therapy to Alternative Drugs

After patients achieve adequate control of the heart rate and a stable clinical status, transition to alternative antiarrhythmic drugs may be accomplished.

When transitioning from Brevibloc injection to alternative drugs, the physician should carefully consider the labeling instructions of the alternative drug selected and reduce the dosage of Brevibloc injection as follows:

1. Thirty minutes following the first dose of the alternative drug, reduce the Brevibloc infusion rate by one-half (50%).
2. After administration of the second dose of the alternative drug, monitor the patient's response and if satisfactory control is maintained for the first hour, discontinue the Brevibloc infusion.

• 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 injection'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 moxonidine below.)
• Brevibloc injection 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 injection leads to an approximate 10% to 20% increase of digoxin blood levels at some time points.
• Digoxin does not affect Brevibloc injection pharmacokinetics. Both digoxin and beta blockers slow atrioventricular conduction and decrease heart rate. Concomitant use increases the risk of bradycardia.
• Anticholinesterases: Brevibloc injection 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 injection 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 injection.
• Vasoconstrictive and positive inotropic agents: Because of the risk of reducing cardiac contractility in presence of high systemic vascular resistance, do not use Brevibloc injection to control tachycardia in patients receiving drugs that are vasoconstrictive and have positive inotropic effects, such as epinephrine, norepinephrine, and dopamine.

• There are no adequate and well-controlled studies in pregnant women. Brevibloc injection should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
• It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk and because of the potential for serious adverse reactions in nursing infants from Brevibloc, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.