Brand Name
Intropin, Revimine (CAN)
Class and Category
Chemical class: Catecholamine
Therapeutic class: Cardiac stimulant, vasopressor
Pregnancy category: C
Indications and Dosages
To correct hypotension that’s unresponsive to adequate
fluid volume replacement or occurs as part of shock syndrome\ caused by
bacteremia, chronic cardiac decompensation, drug overdose, MI, open-heart
surgery, renal failure, trauma, or other major systemic illnesses; to improve
low cardiac output
I.V. INFUSION
Adults. 0.5 to 3 mcg/kg/min for vasodilation of renal arteries; 2 to 10
mcg/kg/min for positive inotropic effects and increased cardiac output; 10
mcg/kg/min, increased gradually according to patient’s response, for increased
systolic and diastolic blood pressures.
DOSAGE ADJUSTMENT
Initial dosage reduced to 10% of usual amount if patient has taken
MAO inhibitor in previous 2 to 3 wk.
Children. 1 to 5 mcg/kg/min increased gradually in
increments of 2.5 to 5 mcg/kg/min to achieve desired results. Maximum: 20
mcg/kg/min.
Route Onset
Peak Duration
I.V. In
5 min Unknown Up to 10min
Mechanism of Action
Stimulates dopamine1 (D1) and dopamine2 (D2) postsynaptic
receptors. D1 receptors mediate vasodilation in renal, mesenteric, coronary,
and cerebral blood vessels. D2 receptors inhibit norepinephrine release. In higher
doses, dopamine also stimulates alpha1 and alpha2 receptors, causing vascular smooth-muscle
contraction. At doses of 0.5 to 3 mcg/kg/min, this naturally occurring
catecholamine mainly affects dopaminergic receptors in renal, mesenteric,
coronary, and cerebral vessels, resulting in vasodilation, increased renal blood
flow, improved GFR, and increased urine output. At doses of 2 to 10 mcg/kg/ min,
dopamine stimulates beta1-adrenergic receptors, increasing cardiac output while
maintaining dopaminergic-induced vasodilation. At doses of 10 mcg/kg/min or
more, alpha-adrenergic agonism takes over, causing increased peripheral
vascular resistance and renal vasoconstriction.
Incompatibilities
Don’t add dopamine to 5% sodium bicarbonate, alkaline I.V.
solutions, oxidizing agents, or iron salts.
Contraindications
Pheochromocytoma, uncorrected ventricular fibrillation,
ventricular tachycardia, and other tachyarrhythmias
Interactions
DRUGS
alpha blockers, haloperidol, loxapine, phenothiazines, thioxanthenes:
Antagonized peripheral vasoconstriction with high doses of
dopamine
anesthetics, such as chloroform, enflurane, halothane, isoflurane,
and methoxyflurane: Increased risk of severe atrial and ventricular arrhythmias
antihypertensives, diuretics used as antihypertensives: Possibly
decreased antihypertensive effects of these drugs
beta blockers: Antagonized beta receptor– mediated inotropic
effects of dopamine
digitalis glycosides: Possibly increased risk of arrhythmias
and additive inotropic effects
diuretics: Possibly increased diuretic effects of
dopamine or diuretic
doxapram: Possibly increased vasopressor effects of
dopamine or doxapram
ergot alkaloids: Enhanced peripheral
vasoconstriction
guanadrel, guanethidine: Possibly decreased hypotensive
effects of these drugs and potentiated vasopressor response to dopamine,
resulting in hypertension and arrhythmias
levodopa: Increased risk of arrhythmias
MAO inhibitors: Prolonged and intensified cardiac
stimulation and vasopressor effect
maprotiline, tricyclic antidepressants: Possibly
potentiated cardiovascular and vasopressor effects of dopamine,
resulting in arrhythmias, hyperpyrexia, or severe hypertension
mecamylamine, methyldopa: Possibly decreased hypotensive
effects of these drugs and enhanced vasopressor effect of dopamine
methylphenidate: Possibly potentiated vasopressor effect
of dopamine
nitrates: Possibly decreased antianginal effects of
nitrates; possibly decreased vasopressor effect of dopamine, resulting in hypotension
oxytocic drugs: Possibly severe hypertension
phenoxybenzamine: Possibly antagonized peripheral
vasoconstriction of dopamine, causing hypotension and tachycardia
phenytoin: Possibly sudden bradycardia and hypotension
rauwolfia alkaloids: Possibly decreased hypotensive effects
of these drugs
sympathomimetics: Possibly increased adverse
cardiovascular and other effects
thyroid hormones: Increased risk of coronary insufficiency
Adverse Reactions
CNS: Headache
CV: Angina, bradycardia, hypertension, hypotension, palpitations,
peripheral vasoconstriction, sinus tachycardia, ventricular arrhythmias
GI: Nausea, vomiting
RESP: Dyspnea
SKIN: Extravasation with tissue necrosis
Nursing Considerations
• If possible, avoid giving dopamine to patients with occlusive
vascular disease, such as atherosclerosis, Buerger’s disease, diabetic
endarteritis, or Raynaud’s disease, because of risk of decreased peripheral
circulation.
• Use drug cautiously in patients with cardiac disease,
particularly coronary artery disease, because dopamine increases myocardial
oxygen demand. Also use drug cautiously in patients allergic to sulfites, which
are contained in some forms of dopamine.
• Inspect parenteral solution for particles and discoloration
before administration.
• Dilute dopamine concentrate with a compatible I.V. solution
before administering. Typical dilution is 400 mg in 250 ml to yield 1.6 mg/ml.
Don’t exceed 3.2 mg/ml.
• If patient has hypovolemia, ensure adequate fluid resuscitation
before giving drug.
• Give drug by I.V. infusion using an infusion pump.
WARNING When infusion rate exceeds 20 mcg/kg/min,
monitor patient for excessive vasoconstriction and loss of renal vasodilating
effects. Avoid using an infusion rate above 50 mcg/kg/min.
• If you must infuse more than 20 mcg/kg/ min of dopamine to
maintain blood pressure, expect to infuse norepinephrine as prescribed.
• To avoid extravasation and tissue necrosis, administer infusion
through a central catheter. If you must give drug via peripheral line, inspect
site often for signs of extravasation and necrosis. If you detect such signs,
start a new I.V. line for dopamine infusion, discontinue previous I.V. line,
and notify prescriber immediately.
• If drug extravasates, expect to give 5 to 10 mg phentolamine
diluted in 10 to 15 ml normal
saline solution, as prescribed. Phentolamine
infiltrates directly into area to antagonize
vasoconstriction and minimize sloughing and
tissue necrosis.
•Titrate
dopamine gradually to minimize hypotension, especially after a high infusion rate.
•Monitor
blood pressure continuously with an intra-arterial line, as indicated.
•
Place patient on continuous ECG monitoring, and assess heart rate and rhythm for
arrhythmias.
•Monitor
patient’s hemodynamic parameters, such as central venous pressure, pulmonary artery
wedge pressure, and cardiac output, as indicated, to assess effectiveness of
dopamine therapy.
•Monitor
urine output hourly as appropriate to assess patient for improved renal blood
flow.
PATIENT
TEACHING
•
Explain the need for frequent hemodynamic monitoring.
