DOPAMINE

Shock States: Used in the treatment of various types of shock, including cardiogenic and septic shock, to improve blood pressure and cardiac output.
Heart Failure: Administered in patients with heart failure to improve cardiac output.
Renal Perfusion: Low-dose dopamine has historically been used to improve renal blood flow, though this use is now controversial due to limited evidence.

1-3 mcg/kg/min: Stimulates dopamine receptors, leading to vasodilation in renal and mesenteric arteries.

3-10 mcg/kg/min: Stimulates beta-1 adrenergic receptors, enhancing myocardial contractility and heart rate.

10-20 mcg/kg/min: Activates alpha-1 adrenergic receptors, causing vasoconstriction and increasing systemic vascular resistance.

Renal Impairment: Monitor renal function; benefits of low-dose dopamine for renal perfusion are questionable.
Hepatic Impairment: No specific dose adjustment guidelines, but close monitoring is advised.
Heart Failure: Prefer medium doses for improving cardiac output without excessive vasoconstriction.
Shock States: Titrate doses based on blood pressure response and organ perfusion.

Absorption: Not effective orally due to rapid metabolism.
Distribution: Rapidly distributed in extracellular fluid.
Metabolism: Metabolized in the liver, kidneys, and plasma by monoamine oxidase (MAO) and catechol-O-methyltransferase (COMT).
Elimination Half-Life: Approximately 2 minutes.
Excretion: Primarily excreted in urine as metabolites.

Low Doses (1-3 mcg/kg/min): Dopamine receptor activation causes vasodilation, particularly in the renal and mesenteric arteries.
Medium Doses (3-10 mcg/kg/min): Beta-1 adrenergic receptor stimulation increases myocardial contractility and heart rate.
High Doses (>10 mcg/kg/min): Alpha-1 adrenergic receptor activation induces vasoconstriction and increases systemic vascular resistance.

Monoamine Oxidase Inhibitors (MAOIs): Potentiates the effects of dopamine, leading to severe hypertension.
Beta-Blockers: May reduce the positive inotropic effects of dopamine.
General Anesthetics: Increased risk of arrhythmias.
Phenytoin: May cause severe hypotension and bradycardia.

Extravasation Risk: Dopamine can cause tissue necrosis if extravasation occurs; administer phentolamine as an antidote if extravasation happens.
Hypertension: Monitor blood pressure closely, particularly at high doses.
Arrhythmias: Use with caution in patients with arrhythmias or heart disease.
Pregnancy and Lactation: Use only if the potential benefit justifies the risk.
Tachycardia: Monitor heart rate and reduce dosage if excessive tachycardia occurs.

Common: Tachycardia, arrhythmias, nausea, and hypertension.
Serious: Tissue ischemia at high doses due to vasoconstriction, potential extravasation leading to tissue necrosis, and profound hypotension in some cases.

Septic Shock: Current guidelines recommend norepinephrine as the first-line vasopressor, with dopamine reserved for select patients without tachyarrhythmias.
Renal Protection: Low-dose dopamine is no longer recommended for renal protection in critically ill patients.
Cardiogenic Shock: Dopamine may be used as an alternative to norepinephrine based on individual patient response.

Dopamine - NCBI StatPearls: https://www.ncbi.nlm.nih.gov/books/NBK535451/
Stoelting’s Pharmacology and Physiology in Anesthetic Practice, 5th Edition: Comprehensive reference on pharmacology.
Katzung & Trevor's Basic and Clinical Pharmacology, 14th Edition: Detailed information on dopamine's pharmacological properties.
Surviving Sepsis Campaign Guidelines (2021): Updated recommendations for vasopressor use in sepsis.
American Heart Association Guidelines (2020): Recommendations for vasopressor use in cardiogenic shock.