DOBUTAMINE HYDROCHLORIDE

DOBUTAMINE HYDROCHLORIDe
(doe-byoo'ta-meen)
Dobutrex
Classifications: beta-adrenergic agonist; catecholamine;
Therapeutic: cardiac stimulant
Prototype: Isoproterenol
Pregnancy Category: C

Availability

12.5 mg/mL injection

Action

Produces inotropic effect by acting on beta receptors and primarily on myocardial alpha-adrenergic receptors. Increases cardiac output and decreases pulmonary wedge pressure and total systemic vascular resistance with comparatively little or no effect on BP. Also increases conduction through AV node, and has lower potential for precipitating arrhythmias than dopamine.

Therapeutic Effect

In CHF or cardiogenic shock it increases cardiac output, enhances renal perfusion, increases renal output, and renal sodium excretion.

Uses

Inotropic support in short-term treatment of adults with cardiac decompensation due to depressed myocardial contractility (cardiogenic shock) resulting from either organic heart disease or from cardiac surgery.

Unlabeled Uses

To augment cardiovascular function in children undergoing cardiac catheterization, stress thallium testing.

Contraindications

History of hypersensitivity to other sympathomimetic amines or sulfites, ventricular tachycardia, idiopathic hypertrophic subaortic stenosis; hypovolemia; pregnancy (category C); children <2 y.

Cautious Use

Preexisting hypertension, hypotension; atrial fibrillation; acute MI; unstable angina, severe coronary artery disease.

Route & Dosage

Cardiac Decompensation
Adult: IV 0.5–1 mcg/kg/min then titrate up to 2.5–15 mcg/kg/min (max: 40 mcg/kg/min)
Adolescent/Child: IV 2–20 mcg/kg/min

Administration

Intravenous

PREPARE: Continuous: ??Reconstitute by adding 10 mL sterile water for injection or D5W to 250-mg vial; if not completely dissolved, add an additional 10 mL of diluent.??Further dilution is typical (e.g., 250 mg in 1000 mL yields 250 mcg/mL; 250 mg in 500 mL yields 500 mcg/mL; 250 mg in 250 mL yields 1000 mcg/mL).??Use IV solutions within 24 h.

ADMINISTER: Continuous: ??Rate of infusion is determined by body weight and controlled by an infusion pump (preferred) or a microdrip IV infusion set.??IV infusion rate and duration of therapy are determined by heart rate, blood pressure, ectopic activity, urine output, and whenever possible, by measurements of cardiac output and central venous or pulmonary wedge pressures.

INCOMPATIBILITIES Solution/additive: Acyclovir, alteplase, aminophylline, bretylium, bumetanide, calcium chloride, calcium gluconate, diazepam, digoxin, furosemide, heparin, insulin, magnesium sulfate, phenytoin, potassium chloride, potassium phosphate, sodium bicarbonate. Y-site: Acyclovir, alteplase, aminophylline, amphotericin B cholesteryl sulfate, cefepime, foscarnet, furosemide, heparin, indomethacin, lansoprazole, pantoprazole, pemetrexed, phytonadione, piperacillin/tazobactam, thiopental, warfarin.

Refrigerate reconstituted solution at 2°–15° C (36°–59° F) for 48 h or store for 6 h at room temperature.

Adverse Effects (≥1%)

All: Generally dose related. CNS: Headache, tremors, paresthesias, mild leg cramps, nervousness, fatigue (with overdosage). CV: Increased heart rate and BP, premature ventricular beats, palpitation, anginal pain. GI: Nausea, vomiting. Other: Nonspecific chest pain, shortness of breath.

Interactions

Drug: general anesthetics (especially cyclopropane and halothane) may sensitize myocardium to effects of catecholamines such as dobutamine and lead to serious arrhythmias—use with extreme caution; beta-adrenergic blocking agents (e.g., metoprolol, propranolol) may make dobutamine ineffective in increasing cardiac output, but total peripheral resistance may increase—concomitant use generally avoided; mao inhibitors, tricyclic antidepressants potentiate pressor effects—use with extreme caution.

Pharmacokinetics

Onset: 2–10 min. Peak: 10–20 min. Metabolism: Metabolized in liver and other tissues by COMT. Elimination: In urine. Half-Life: 2 min.

Nursing Implications

Assessment & Drug Effects

Correct hypovolemia by administration of appropriate volume expanders prior to initiation of therapy.
Monitor therapeutic effectiveness. At any given dosage level, drug takes 10–20 min to produce peak effects.
Monitor ECG and BP continuously during administration.
Note: Marked increases in blood pressure (systolic pressure is the most likely to be affected) and heart rate, or the appearance of arrhythmias or other adverse cardiac effects are usually reversed promptly by reduction in dosage.
Observe patients with preexisting hypertension closely for exaggerated pressor response.
Note: Tolerance has been observed with continuous or prolonged infusions; adverse reactions are no different than those seen with shorter infusions.
Monitor I&O ratio and pattern. Urine output and sodium excretion generally increase because of improved cardiac output and renal perfusion.

Patient & Family Education

Report anginal pain to physician promptly.

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug

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