BREVIBLOC- esmolol hydrochloride_injection

BREVIBLOC (Esmolol Hydrochloride) injection is a beta 1 1 2 Clinical pharmacology studies in normal volunteers have confirmed the beta blocking activity of BREVIBLOC injection, showing reduction in heart rate at rest and during exercise, and attenuation of isoproterenol-induced increases in heart rate. Blood levels of BREVIBLOC injection have been shown to correlate with extent of beta blockade. After termination of infusion, substantial recovery from beta blockade is observed in 10‑20 minutes. The acid metabolite of esmolol exhibits negligible pharmacological activity. In human electrophysiology studies, BREVIBLOC injection produced effects typical of a beta blocker: a decrease in the heart rate, increase in sinus cycle length, prolongation of the sinus node recovery time, prolongation of the AH interval during normal sinus rhythm and during atrial pacing, and an increase in antegrade Wenckebach cycle length. In patients undergoing radionuclide angiography, BREVIBLOC injection, at dosages of 200 mcg/kg/min, produced reductions in heart rate, systolic blood pressure, rate pressure product, left and right ventricular ejection fraction and cardiac index at rest, which were similar in magnitude to those produced by intravenous propranolol (4 mg). During exercise, BREVIBLOC injection produced reductions in heart rate, rate pressure product and cardiac index which were also similar to those produced by propranolol, but BREVIBLOC injection produced a significantly larger fall in systolic blood pressure. In patients undergoing cardiac catheterization, the maximum therapeutic dose of 300 mcg/kg/min of BREVIBLOC injection produced similar effects and, in addition, there were small, clinically insignificant increases in the left ventricular end diastolic pressure and pulmonary capillary wedge pressure. At 30 minutes after the discontinuation of BREVIBLOC infusion, all of the hemodynamic parameters had returned to pretreatment levels. The relative cardioselectivity of BREVIBLOC injection was demonstrated in 10 mildly asthmatic patients. Infusions of BREVIBLOC injection 100, 200 and 300 mcg/kg/min produced no significant increases in specific airway resistance compared to placebo. At 300 mcg/kg/min, BREVIBLOC injection produced slightly enhanced bronchomotor sensitivity to dry air stimulus. These effects were not clinically significant, and BREVIBLOC injection was well tolerated by all patients. Six of the patients also received intravenous propranolol, and at a dosage of 1 mg, two experienced significant, symptomatic bronchospasm requiring bronchodilator treatment. One other propranolol-treated patient also experienced dry air-induced bronchospasm. No adverse pulmonary effects were observed in patients with COPD who received therapeutic dosages of BREVIBLOC injection for treatment of supraventricular tachycardia (51 patients) or in perioperative settings (32 patients). Esmolol is rapidly metabolized by hydrolysis of the ester linkage, chiefly by the esterases in the cytosol of red blood cells and not by plasma cholinesterases or red cell membrane acetylcholinesterase. Total body clearance in man was found to be about 20 L/kg/hr, which is greater than cardiac output; thus the metabolism of esmolol is not limited by the rate of blood flow to metabolizing tissues such as the liver or affected by hepatic or renal blood flow. Esmolol has a rapid distribution half-life of about 2 minutes and an elimination half-life of about 9 minutes. Using an appropriate loading dose, steady-state blood levels of BREVIBLOC injection for dosages from 50-300 mcg/kg/min are obtained within five minutes. Steady-state is reached in about 30 minutes without the loading dose. Steady-state blood levels of esmolol increase linearly over this dosage range and elimination kinetics are dose-independent over this range. Steady-state blood levels are maintained during infusion but decrease rapidly after termination of the infusion. Because of its short half-life, blood levels of esmolol can be rapidly altered by increasing or decreasing the infusion rate and rapidly eliminated by discontinuing the infusion. Consistent with the high rate of blood-based metabolism of esmolol, less than 2% of the drug is excreted unchanged in the urine. Within 24 hours of the end of infusion, the acid metabolite of esmolol in urine accounts for approximately 73-88% of the dosage. Metabolism of esmolol results in the formation of the corresponding free acid and methanol. The acid metabolite has been shown in animals to have negligible activity and in normal volunteers its blood levels do not correspond to the level of beta blockade. The acid metabolite has an elimination half-life of about 3. 7 hours and is excreted in the urine with a clearance approximately equivalent to the glomerular filtration rate. After a 4 hour maintenance infusion of 150 mcg/kg, the plasma concentrations of esmolol are similar in subjects with normal renal function and in patients with ESRD on dialysis. The half-life of the acid metabolite of BREVIBLOC injection, which is primarily excreted unchanged by the kidney, is increased about 12-fold to 48 hours in patients with ESRD. The peak concentrations of the acid metabolite are doubled in ESRD. Methanol blood levels, monitored in subjects receiving BREVIBLOC injection for up to 6 hours at 300 mcg/kg/min and 24 hours at 150 mcg/kg/min, approximated endogenous levels and were less than 2% of levels usually associated with methanol toxicity. BREVIBLOC injection has been shown to be 55% bound to human plasma protein, while the acid metabolite is only 10% bound.

BREVIBLOC injection is a beta adrenergic blocker indicated for the short-term treatment of: 1. 2 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. 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.

1 2. 2 2. 2 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 Step Action 1 Optional loading dose (500 mcg per kg over 1 minute), then 50 mcg per kg per min for 4 min 2 Optional loading dose if necessary, then 100 mcg per kg per min for 4 min 3 Optional loading dose if necessary, then 150 mcg per kg per min for 4 min 4 If necessary, increase dose to 200 mcg per kg per min 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. 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 Gradual Control Maximum Recommended Doses 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. BREVIBLOC injection is available in a pre-mixed bag and ready-to-use vial. BREVIBLOC injection is not compatible with Sodium Bicarbonate (5%) solution (limited stability) or furosemide (precipitation). Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit. Premixed Bag Figure 1: Two-Port INTRAVIA Bag Ready-to-Use Vial The Ready-to-use Vial may be used to administer a loading dosage by hand-held syringe while the maintenance infusion is being prepared [see How Supplied/Storage and Handling (16. 2) Compatibility with Commonly Used Intravenous Fluids BREVIBLOC injection was tested for compatibility with ten commonly used intravenous fluids at a final concentration of 10 mg esmolol hydrochloride per mL. BREVIBLOC injection was found to be compatible with the following solutions and was stable for at least 24 hours at controlled room temperature or under refrigeration: Figure 1: Two-port INTRAVIA Bag.

Most common adverse reactions (incidence >10%) are symptomatic hypotension (hyperhidrosis, dizziness) and asymptomatic hypotension ( 6 To report SUSPECTED ADVERSE REACTIONS, contact Baxter Healthcare Corporation at 1-866-888-2472 or FDA at 1-800-FDA-1088 or www. gov/medwatch. Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice. The following adverse reaction rates are based on use of BREVIBLOC (Esmolol Hydrochloride) injection in clinical trials involving 369 patients with supraventricular tachycardia and over 600 intraoperative and postoperative patients enrolled in clinical trials. Most adverse effects observed in controlled clinical trial settings have been mild and transient. The most important and common adverse effect has been hypotension [see Warnings and Precautions (5. 1) [see Warnings and Precautions (5. 5) Table 3 Clinical Trial Adverse Reactions (Frequency >=3%) System Organ Class (SOC) Preferred MedDRA Term Frequency VASCULAR DISORDERS Hypotension* 25% 12% GENERAL DISORDERS AND ADMINISTRATION SITE CONDITIONS Infusion site reactions 8% GASTROINTESTINAL DISORDERS Nausea 7% NERVOUS SYSTEM DISORDERS Dizziness 3% Somnolence 3% * Clinical Trial Adverse Reactions (Frequency <3%) Psychiatric Disorders Confusional state and agitation (~2%) Nervous System Disorders Headache (~ 2%) Vascular Disorders Peripheral ischemia (~1%) Gastrointestinal Disorders Vomiting (~1%) Renal and Urinary Disorders Urinary retention (<1%) In addition to the adverse reactions reported in clinical trials, the following adverse reactions have been reported in the post-marketing experience. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to estimate reliably their frequency or to establish a causal relationship to drug exposure. Cardiac Disorders Cardiac arrest, Coronary arteriospasm Skin and Subcutaneous Tissue Disorders Angioedema, Urticaria, Psoriasis.

BREVIBLOC (Esmolol Hydrochloride) injection is contraindicated in patients with: [see Warnings and Precautions (5. 2) [see Warnings and Precautions (5. 2) 4 4 4 4 4 4 7 4 4.

Esmolol hydrochloride has been shown to produce increased fetal resorptions with minimal maternal toxicity in rabbits when given in doses approximately 8 times the maximum human maintenance dose (300 mcg/kg/min). 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. Teratogenicity studies in rats at intravenous dosages of esmolol hydrochloride up to 3000 mcg/kg/min (10 times the maximum human maintenance dosage) for 30 minutes daily produced no evidence of maternal toxicity, embryotoxicity or teratogenicity, while a dosage of 10,000 mcg/kg/min produced maternal toxicity and lethality. In rabbits, intravenous dosages up to 1000 mcg/kg/min for 30 minutes daily produced no evidence of maternal toxicity, embryotoxicity or teratogenicity, while 2500 mcg/kg/min produced minimal maternal toxicity and increased fetal resorptions. Although there are no adequate and well-controlled studies in pregnant women, use of esmolol in the last trimester of pregnancy or during labor or delivery has been reported to cause fetal bradycardia, which continued after termination of drug infusion. 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 injection, 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. The safety and effectiveness of BREVIBLOC injection in pediatric patients have not been established. Clinical studies of BREVIBLOC injection did not include sufficient numbers of subjects aged 65 and over to determine whether they responded differently from younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. In general, dose selection for an elderly patient should usually start at the low end of the dosing range, reflecting greater frequency of decreased renal or cardiac function and of concomitant disease or other drug therapy. No special precautions are necessary in patients with hepatic impairment because BREVIBLOC injection is metabolized by red-blood cell esterases [see Clinical Pharmacology (12) No dosage adjustment is required for esmolol in patients with renal impairment receiving a maintenance infusion of esmolol 150 mcg/kg for 4 hours. There is no information on the tolerability of maintenance infusions of esmolol using rates in excess of 150 mcg/kg or maintained longer than 4 hours [see Clinical Pharmacology (12).

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: 7 7 7 7 7.

OVERDOSAGE
Overdoses of BREVIBLOC (Esmolol Hydrochloride) injection 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. st nd rd 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 beta 2 Massive accidental overdoses of BREVIBLOC injection have resulted from dilution errors. Use of BREVIBLOC PREMIXED Injection and BREVIBLOC PREMIXED Double Strength 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. 5‑50 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 injection resolved.
NONCLINICAL TOXICOLOGY
Because of its short-term usage, no carcinogenicity, mutagenicity, or reproductive performance studies have been conducted with esmolol.
CLINICAL STUDIES
Supraventricular Tachycardia In two multicenter, randomized, double-blind, controlled comparisons of BREVIBLOC injection with placebo and propranolol, maintenance doses of 50 to 300 mcg/kg/min of BREVIBLOC injection were found to be more effective than placebo and about as effective as propranolol, 3‑6 mg given by bolus injections, in the treatment of supraventricular tachycardia, principally atrial fibrillation and atrial flutter. The majority of these patients developed their arrhythmias postoperatively. About 60-70% of the patients treated with BREVIBLOC injection developed either a 20% reduction in heart rate, a decrease in heart rate to less than 100 bpm, or, rarely, conversion to normal sinus rhythm and about 95% of these patients did so at a dosage of 200 mcg/kg/min or less. The average effective dosage of BREVIBLOC injection was approximately 100 mcg/kg/min in the two studies. Other multicenter baseline-controlled studies gave similar results. In the comparison with propranolol, about 50% of patients in both the BREVIBLOC injection and propranolol groups were on concomitant digoxin. Response rates were slightly higher with both beta blockers in the digoxin-treated patients. In all studies significant decreases of blood pressure occurred in 20-50% of patients, identified either as adverse reaction reports by investigators, or by observation of systolic pressure less than 90 mmHg or diastolic pressure less than 50 mmHg. The hypotension was symptomatic (mainly hyperhidrosis or dizziness) in about 12% of patients, and therapy was discontinued in about 11% of patients, about half of whom were symptomatic. Hypotension was more common with BREVIBLOC injection (53%) than with propranolol (17%). The hypotension was rapidly reversible with decreased infusion rate or after discontinuation of therapy with BREVIBLOC injection. For both BREVIBLOC injection and propranolol, hypotension was reported less frequently in patients receiving concomitant digoxin.

Baxter Healthcare Corporation

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