Dobutamine

INDICATIONS AND USAGE Dobutamine Injection, USP is indicated when parenteral therapy is necessary for inotropic support in the short-term treatment of patients with cardiac decompensation due to depressed contractility resulting either from organic heart disease or from cardiac surgical procedures. Experience with intravenous dobutamine in controlled trials does not extend beyond 48 hours of repeated boluses and/or continuous infusions. Whether given orally, continuously intravenously, or intermittently intravenously, neither dobutamine nor any other cyclic-AMP-dependent inotrope has been shown in controlled trials to be safe or effective in the long-term treatment of congestive heart failure. In controlled trials of chronic oral therapy with various such agents, symptoms were not consistently alleviated, and the cyclic-AMP-dependent inotropes were consistently associated with increased risk of hospitalization and death. Patients with NYHA Class IV symptoms appeared to be at particular risk.

DOSAGE AND ADMINISTRATION Note −Do not add dobutamine injection to 5% Sodium Bicarbonate Injection or to any other strongly alkaline solution. Because of potential physical incompatibilities, it is recommended that dobutamine injection not be mixed with other drugs in the same solution. Dobutamine injection should not be used in conjunction with other agents or diluents containing both sodium bisulfite and ethanol. Preparation and Stability − At the time of administration, dobutamine injection must be further diluted in an IV container to at least a 50-mL solution using one of the following intravenous solutions as a diluent: 5% Dextrose Injection, 5% Dextrose and 0.45% Sodium Chloride Injection, 5% Dextrose and 0.9% Sodium Chloride Injection, 10% Dextrose Injection, Isolyte® M with 5% Dextrose Injection, Lactated Ringer’s Injection, 5% Dextrose in Lactated Ringer’s Injection, Normosol®-M in D5-W, 20% Osmitrol® in Water for Injection, 0.9% Sodium Chloride Injection, or Sodium Lactate Injection. Intravenous solution should be used within 24 hours. Recommended Dosage −Infusion of dobutamine should be started at a low rate (0.5-1.0 μg/kg/min) and titrated at intervals of a few minutes, guided by the patient’s response, including systemic blood pressure, urine flow, frequency of ectopic activity, heart rate, and (whenever possible) measurements of cardiac output, central venous pressure, and/or pulmonary capillary wedge pressure. In reported trials, the optimal infusion rates have varied from patient to patient, usually 2-20 μg/kg/min but sometimes slightly outside of this range. On rare occasions, infusion rates up to 40 μg/kg/min have been required to obtain the desired effect. Rates of infusion (mL/h) for dobutamine injection concentrations of 500 μg/mL, 1,000 μg/mL, and 2,000 μg/mL necessary to attain various delivery rates of dobutamine (μg/kg/min) for patients of different weights are given in Table 1. Table 1 Dobutamine Injection Infusion Rate (mL/h) for 500 μg/mL concentration Drug Delivery Rate (μg/kg/min) Patient Body Weight (kg) 5 10 20 30 40 50 60 70 80 90 100 110 0.5 0.3 0.6 1.2 1.8 2.4 3 3.6 4.2 4.8 5.4 6 6.5 1 0.6 1.2 2.4 3.6 4.8 6 7.2 8.4 9.6 10.8 12 13.2 2.5 1.5 3 6 9 12 15 18 21 24 27 30 33 5 3 6 12 18 24 30 36 42 48 54 60 66 7.5 4.5 9 18 27 36 45 54 63 72 81 90 99 10 6 12 24 36 48 60 72 84 96 108 120 132 12.5 7.5 15 30 45 60 75 90 105 120 135 150 165 15 9 18 36 54 72 90 108 126 144 162 180 198 17.5 10.5 21 42 63 84 105 126 147 168 189 210 231 20 12 24 48 72 96 120 144 168 192 216 240 264 Dobutamine Injection Infusion Rate (mL/h) for 1,000 μg/mL concentration Drug Delivery Rate (μg/kg/min) Patient Body Weight (kg) 5 10 20 30 40 50 60 70 80 90 100 110 0.5 0.1 0.3 0.6 0.9 1.2 1.5 1.8 2.1 2.4 2.7 3 3.3 1 0.3 0.6 1.2 1.8 2.4 3 3.6 4.2 4.8 5.4 6 6.6 2.5 0.7 1.5 3 4.5 6 7.5 9 10.5 12 13.5 15 16.5 5 1.5 3 6 9 12 15 18 21 24 27 30 33 7.5 2.2 4.5 9 13.5 18 22.5 27 31.5 36 40.5 45 49.5 10 3 6 12 18 24 30 36 42 48 54 60 66 12.5 3.7 7.5 15 22.5 30 37.5 45 52.5 60 67.5 75 82.5 15 4.5 9 18 27 36 45 54 63 72 81 90 99 17.5 5.2 10.5 21 31.5 42 52.5 63 73.5 84 94.5 105 115.5 20 6 12 24 36 48 60 72 84 96 108 120 132 Dobutamine Injection Infusion Rate (mL/h) for 2,000 μg/mL concentration Drug Delivery Rate (μg/kg/min) Patient Body Weight (kg) 5 10 20 30 40 50 60 70 80 90 100 110 0.5 0.07 0.1 0.3 0.4 0.6 0.7 0.9 1 1.2 1.3 1.5 1.6 1 0.1 0.3 0.6 0.9 1.2 1.5 1.8 2.1 2.4 2.7 3 3.3 2.5 0.4 0.7 1.5 2 3 4 4.5 5 6 7 7.5 8 5 0.7 1.5 3 4.5 6 7.5 9 10.5 12 13.5 15 16.5 7.5 1.1 2.2 4.5 7 9 11 13.5 16 18 20 22.5 25 10 1.5 3 6 9 12 15 18 21 24 27 30 33 12.5 1.9 3.7 7 11 15 19 22.5 26 30 34 37.5 41 15 2.2 4.5 9 13.5 18 22.5 27 31.5 36 40.5 45 49.5 Concentrations of up to 5,000 mcg/mL have been administered to humans (250 mg/50 mL). The final volume administered should be determined by the fluid requirements of the patient. Intravenous drug products should be inspected visually and should not be used if particulate matter or discoloration is present…

WARNINGS Increase in Heart Rate or Blood Pressure Dobutamine hydrochloride may cause a marked increase in heart rate or blood pressure, especially systolic pressure. Approximately 10% of patients in clinical studies have had rate increases of 30 beats/minute or more, and about 7.5% have had a 50 mm Hg or greater increase in systolic pressure. Usually, reduction of dosage promptly reverses these effects. Because dobutamine hydrochloride facilitates atrioventricular conduction, patients with atrial fibrillation are at risk of developing rapid ventricular response. In patients who have atrial fibrillation with rapid ventricular response, a digitalis preparation should be used prior to institution of therapy with Dobutamine Injection. Patients with pre-existing hypertension appear to face an increased risk of developing an exaggerated pressor response. Ectopic Activity Dobutamine hydrochloride may precipitate or exacerbate ventricular ectopic activity, but it rarely has caused ventricular tachycardia. Hypersensitivity Reactions suggestive of hypersensitivity associated with administration of Dobutamine Injection, including skin rash, fever, eosinophilia, and bronchospasm, have been reported occasionally. Dobutamine Injection contains sodium metabisulfite, a sulfite that may cause allergic-type reactions, including anaphylactic symptoms and life-threatening or less severe asthmatic episodes, in certain susceptible people. The overall prevalence of sulfite sensitivity in the general population is unknown and probably low. Sulfite sensitivity is seen more frequently in asthmatic than in nonasthmatic people.

CONTRAINDICATIONS Dobutamine hydrochloride is contraindicated in patients with idiopathic hypertrophic subaortic stenosis and in patients who have shown previous manifestations of hypersensitivity to Dobutamine Injection solution.

Drug Interactions Animal studies indicate that dobutamine may be ineffective if the patient has recently received a β-blocking drug. In such a case, the peripheral vascular resistance may increase. Preliminary studies indicate that the concomitant use of dobutamine and nitroprusside results in a higher cardiac output and, usually, a lower pulmonary wedge pressure than when either drug is used alone. There was no evidence of drug interactions in clinical studies in which dobutamine was administered concurrently with other drugs, including digitalis preparations, furosemide, spironolactone, lidocaine, nitroglycerin, isosorbide dinitrate, morphine, atropine, heparin, protamine, potassium chloride, folic acid, and acetaminophen.

Pregnancy Teratogenic Effects −Reproduction studies performed in rats at doses up to the normal human dose (10 mcg/kg/min for 24 h, total daily dose of 14.4 mg/kg), and in rabbits at doses up to twice the normal human dose, have revealed no evidence of harm to the fetus due to dobutamine hydrochloride. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.

Nursing Mothers It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when dobutamine hydrochloride is administered to a nursing woman. If a mother requires dobutamine hydrochloride treatment, breastfeeding should be discontinued for the duration of treatment.

ADVERSE REACTIONS Increased Heart Rate, Blood Pressure, and Ventricular Ectopic Activity − A 10 to 20 mm increase in systolic blood pressure and an increase in heart rate of 5 to 15 beats/minute have been noted in most patients (see WARNINGS regarding exaggerated chronotropic and pressor effects). Approximately 5% of patients have had increased premature ventricular beats during infusions. These effects are dose related. Hypotension − Precipitous decreases in blood pressure have occasionally been described in association with dobutamine therapy. Decreasing the dose or discontinuing the infusion typically results in rapid return of blood pressure to baseline values. In rare cases, however, intervention may be required and reversibility may not be immediate. Reactions at Sites of Intravenous Infusion − Phlebitis has occasionally been reported. Local inflammatory changes have been described following inadvertent infiltration. Isolated cases of cutaneous necrosis (destruction of skin tissue) have been reported. Miscellaneous Uncommon Effects − The following adverse effects have been reported in 1% to 3% of patients: nausea, headache, anginal pain, nonspecific chest pain, palpitations and shortness of breath. Isolated cases of thrombocytopenia have been reported. Administration of dobutamine hydrochloride, like other catecholamines, can produce a mild reduction in serum potassium concentration, rarely to hypokalemic levels (see PRECAUTIONS ).