Description: Dopamine is a catecholamine and a precursor to norepinephrine and epinephrine. It is a sympathomimetic agent, meaning it mimics the effects of sympathetic nervous system stimulation. It is available as a solution for intravenous injection.

Indication: Dopamine is used to treat various conditions, including:

• Shock (septic shock, cardiogenic shock, and traumatic shock)

• Heart failure

• Hypotension (low blood pressure)

• Bradycardia (slow heart rate)

Mechanism of Action: Dopamine’s effects are dose-dependent:

• Low doses (0.5-2 mcg/kg/min): Primarily stimulates dopaminergic receptors, leading to vasodilation in the renal, mesenteric, coronary, and cerebral arteries. This increases blood flow to the kidneys, which can increase urine output.

• Intermediate doses (2-10 mcg/kg/min): Stimulates beta-1 adrenergic receptors in the heart, leading to increased heart rate and myocardial contractility (the force of heart muscle contraction). This improves cardiac output.

• High doses (>10 mcg/kg/min): Primarily stimulates alpha-1 adrenergic receptors, causing vasoconstriction (narrowing of blood vessels) in the peripheral arteries. This increases systemic vascular resistance and blood pressure.