Dopamine is recommended for the correction of haemodynamic imbalance present in-
- Acute hypotension or shock associated with myocardial infarction, endotoxic septicaemia, trauma and renal failure.
- As an adjunct after open heart surgery, where there is persistent hypotension after correction of hypovolaemia.
- In chronic cardiac decompensation as in congestive failure.
Dopamine Hydrochloride Injection is a clear and colorless solution for intravenous infusion after dilution.
Dopamine hydrochloride can stimulate alpha, beta and dopamine receptors. At infusion rates of 0.5 to 2 micrograms/kg/min, dopamine receptors are selectively activated and blood pressure either does not change or decrease slightly. The most important effects are renal and mesenteric vasodilatation. Renal plasma flow, glomerular filtration rate and sodium excretion usually increase. At infusion rates of 2 to 10 micrograms/kg/min, beta1-receptors are activated and cardiac output and systolic blood pressure increase.
Dopamine stimulates dopaminergic receptors at lower doses producing renal and mesenteric vasodilation; at higher doses stimulates both dopaminergic and β1-adrenergic receptors producing cardiac stimulation and renal vasodilation; large doses stimulates α-adrenergic receptors.
Acute heart failure:
- Adult: Initially, 2-5 mcg/kg/min, increased gradually by up to 5-10 mcg/kg/min according to patient’s cardiac and urine output. Seriously ill patient: Up to 20-50 mcg/kg/min may be required.
Cyclopropane and halogenated hydrocarbon anaesth may enhance the arrhythmogenic effect of dopamine. Cardiac effects are antagonised by β-adrenergic agents (e.g. propanolol, metoprolol). α-adrenergic blocking agents may antagonise the vasoconstricting effect of high dose dopamine. Prolonged and enhanced effect with MAOIs. Risk of hypotension and bradycardia with phenytoin. May potentiate diuretic effect of hydrochlorothiazide or furosemide. Enhanced vasopressor effect with TCAs and guanethidine. Risk of excessive vasoconstriction with ergot alkaloids.
Administration of dopamine is contraindicated in the following cases: Pheochromocytoma, atrial or ventricular tachyarrhythmias, ventricular fibrillation, hyperthyroidism, concurrent use with ergotamine.
Ectopic heartbeats, angina, tachycardia, palpitation, hypotension, vasoconstriction, dyspnoea, nausea, vomiting, headache, cardiac conduction abnormalities, HTN, azotemia, anxiety, widened QRS complex, bradycardia, piloerection, peripheral cyanosis.
It is not known whether dopamine crosses the placental barrier. The benefits of using this product should be weighed against the possible risks to the fetus.
Lactation: It is not recommended for breast-feeding mothers unless the expected benefits outweigh any potential risks.
Patient with CV disease, cardiac arrhythmias and/or occlusive vascular disease, active myocardial ischaemia or recent MI. Correct hypovolaemia prior to treatment. Pregnancy and lactation.
Symptoms: Excessive BP elevation, vasoconstriction.
Management: Reduce dose or discontinue infusion. May also consider infusion of phentolamine mesylate.
Dilute solution (usually 1.6 mg/ml or 3.2 mg/ml) in glucose 5%, NaCl 0.9% or other suitable diluent. More dilute solution may be used where fluid expansion is not a problem.
Store below 30 °C and protect from light.