Brand Name
Dobutrex
Class and Category
Chemical class: Synthetic catecholamine
Therapeutic class: Cardiac stimulant
Pregnancy category: Not rated
Indications and Dosages
To treat low cardiac output and heart failure
I.V. INFUSION
Adults. 2.5 to 10 mcg/kg/min as continuous infusion adjusted according to
hemodynamic response.
Children. 5 to 20 mcg/kg/min as continuous infusion
adjusted according to hemodynamic response.
Route Onset
Peak Duration
I.V. 1–2
min Unknown Under 5 min
Mechanism of Action
Mainly stimulates beta1-adrenergic receptors, and mildly
stimulates beta2- and alpha1-adrenergic receptors. Beta1-receptor stimulation
produces a positive inotropic effect on the myocardium, increasing cardiac output
by boosting myocardial contractility and stroke volume. Increased myocardial contractility
raises coronary blood flow and myocardial oxygen consumption. Systolic blood
pressure typically rises as a result of increased stroke volume. Other
hemodynamic effects include decreased systemic vascular resistance, which
reduces afterload, and decreased ventricular filling pressure, which reduces
preload.
Incompatibilities
Don’t combine dobutamine with cefamandole, cefazolin,
hydrocortisone sodium succinate, cephalothin, penicillin, sodium ethycrynate, and
sodium heparin because of incompatibility. Don’t mix dobutamine with alkaline
solutions, such as sodium bicarbonate, because of possible physical incompatibility.
Don’t use diluents that contain sodium bisulfite or ethanol.
Contraindications
Hypersensitivity to dobutamine or its components, idiopathic
hypertrophic subaortic stenosis
Interactions
DRUGS
beta blockers: Possibly increased alphaadrenergic activity
and peripheral resistance
bretylium: Potentiated vasopressor activity, possibly
arrhythmias cyclopropane, halothane: Possibly serious arrhythmias
guanethidine: Decreased hypotensive effect of guanethidine,
possibly resulting in severe hypertension
thyroid hormones: Increased cardiovascular effects
of thyroid hormones or dobutamine
tricyclic antidepressants: Possibly potentiated cardiovascular
and vasopressor effects of dobutamine, resulting in arrhythmias, hyperpyrexia,
or severe hypertension
Adverse Reactions
CNS: Fever, headache, nervousness, restlessness
CV: Angina, bradycardia, hypertension, hypotension, palpitations,
PVCs, tachycardia
GI: Nausea, vomiting
RESP: Dyspnea
SKIN: Extravasation with tissue necrosis and sloughing, rash
Other: Hypokalemia
• Avoid giving dobutamine to patients with uncorrected
hypovolemia. Expect prescriber to order whole blood or plasma volume expanders
to correct hypovolemia. Also avoid giving dobutamine to patients with acute MI
because it can intensify or extend myocardial ischemia.
• Use drug cautiously in patients allergic to sulfites because
drug may cause anaphylactic- like signs and symptoms; commercially available
dobutamine injections contain sodium bisulfite. Also use drug cautiously in
patients with atrial fibrillation because drug increases AV conduction. Keep in
mind that patient should be adequately digitalized before administration.
• Dilute concentrate with at least 50 ml compatible I.V. solution.
A common dilution is 500 mg (40 ml from 250-ml bag) in 210 ml D5W or normal
saline solution to yield 2,000 mcg/ml. Or dilute 1,000 mg (80 ml from 250-ml
bag) in 170 ml D5W or normal saline solution to yield 4,000 mcg/ml. Adjust
maximum concentration according to patient’s fluid requirements as prescribed.
Don’t exceed 5,000 mcg/ml. Discard solution after 24 hours.
• Inspect parenteral solution for particles and discoloration
before administering it.
• Give I.V. drug using an infusion pump.
•Monitor blood pressure often during therapy, preferably by
continuous intraarterial monitoring; systolic increase of 10 to 20 mm Hg may
indicate dobutamineinduced increase in cardiac output.
• If hypotension develops, expect to reduce dosage or discontinue
drug.
•Monitor heart rate and rhythm continuously for PVCs, which may
result from drug’s stimulatory effect on heart’s conduction system, and sinus
tachycardia, which results from positive chronotropic effect of beta
stimulation and may increase heart rate by 5 to 15 beats/ minute.
•Monitor hemodynamic parameters, such as central venous pressure,
pulmonary artery wedge pressure, and cardiac output, as indicated, to assess
drug’s effectiveness.
WARNING Monitor serum potassium level to check for
hypokalemia, a rare result of beta2 stimulation that causes electrolyte imbalance.
•Monitor urine output hourly, as appropriate, to check for
improved renal blood flow.
• Dobutamine isn’t indicated for long-term treatment of heart
failure because it may not be effective and may increase the risk of
hospitalization and death.
PATIENT TEACHING
•Explain the need for frequent hemodynamic monitoring.
