Dopamine

Dopamine

Clinical data
Drug class	Endogenous catecholamine
Uses	Treatment of hypotension and bradycardia
Contraindications	pheochromocytoma, ventricular tachycardia, ventricular fibrillation, corn or sulfite hypersensitivities
Routes of administration	Intravenous
Dosage
Pharmacodynamics
Mechanism of action	Dopaminergic and adrenergic agonism
Adverse effects	Arrhythmia and ectopy, tachycardia, hypotension, hypertension, headahce, vomiting, dyspnea, peripheral vasoconstriction and tissue necrosis
Pharmacokinetics
Onset of action	5 minutes
Duration of action	10 minutes
Metabolism	MAO and COMT activity in liver, kidneys, plasma
Physical and chemical data
Formula	C8H11NO2
Molar mass	153.18 g/mol
Article quality
Editor rating	Unrated
User likes	0

Dopamine is a catecholamine with dopaminergic and adrenergic activity. Its primary indication is for the treatment of hypotension and bradycardia in the setting of shock and cardiac arrest. It is also used in the treatment of symptomatic bradycardia that is not responsive to atropine or pacing. It may be used as a palliative infusion for patients with chronic heart failure.

Uses

• Hemodynamic support or treatment of hypotension from shock (septic, cardiogenic, anaphylactic, or neurogenic), open-heart surgery, or renal failure
• Treatment of symptomatic bradycardia unresponsive to atropine and/or external pacing
• Treatment of chronic heart failure

Contraindications

Absolute contraindications

• Pheochromocytoma
• Ventricular tachycardia
• Ventricular fibrillation
• Corn or sulfite hypersensitivities

Precautions

• Asthma
• Hypovolemia
• Occlusive vascular disease
• Raynaud’s phenomenon
• Thromboangiitis obliterans
• Geriatric patients
• Pregnancy or breast-feeding

Pharmacology

Pharmacodynamics

Mechanism of action

Dopamine is an endogenous catecholamine, the metabolic precursor to norepinephrine in the catecholamine synthetic pathway. Dopamine’s affinity for its receptors is dose-dependent. Low infusion rates (0.5 to 2 micrograms/kg per minute) act on dopaminergic D1 and D2 receptors in the visceral vasculature to produce vasodilation and increased blood flow to the kidneys, intestines, heart, and brain. Intermediate infusion rates (from 2 to 10 micrograms/kg/min) continue to stimulate dopaminergic receptors, but also activates beta-1 receptors, increasing myocardial contractility and electrical conductivity in the heart leading to increased cardiac output. Higher doses cause potent vasoconstriction and increased blood pressure via the adrenergic receptors alpha-1, beta-1, and beta-2.

Adverse effects

• Ventricular arrhythmias
• Atrial fibrillation
• PVCs and PACs
• Sinus tachycardia
• Hypotension
• Hypertension
• Headache
• Vomiting
• Dyspnea
• Anxiety
• Piloerection
• Azotemia
• Peripheral vasoconstriction and tissue necrosis

Pharmacokinetics

• Widely distributed throughout the body, but does not cross the blood-brain barrier
• Metabolized in the liver, kidneys, and plasma by monoamine oxidase and catechol-O-methyltransferase
• 25% is taken up into adrenergic nerve terminals, where it is hydroxylated to form norepinephrine
• Excretion of metabolites and conjugates in the urine
• Onset of action: 5 minutes
• Duration of action: 10 minutes

Chemistry and formulation

Dopamine is the prototypical endogenous catecholamine.