Pharmacology · Vasopressors and inotropes
Dopamine !
A natural catecholamine given by intravenous infusion in shock. Its effects change with the dose: dopamine receptors first, then the heart, then the vessels.
Updated 2026-11-01
Also called: 3-hydroxytyramine
The figure shows dopamine bound to the human dopamine D1 receptor in its active complex with a Gs protein.
Mechanism of action
Dopamine is the immediate precursor of norepinephrine. At low doses it acts mainly on dopamine receptors, dilating renal and splanchnic vessels; at moderate doses it stimulates cardiac beta-1 receptors, raising contractility and heart rate; at high doses alpha-1 stimulation constricts vessels. It also releases norepinephrine from nerve endings.
- Low doses: dopamine receptors dilate renal and splanchnic vessels
- Moderate doses: beta-1 stimulation increases contractility and heart rate
- High doses: alpha-1 stimulation constricts vessels and raises blood pressure
Pharmacokinetics
- Metabolism
- Broken down by MAO and COMT; MAO inhibitors prolong and intensify its effect
- Half-life
- Very short: the effect fades within minutes of stopping the infusion
- Onset and duration
- Within minutes of starting the intravenous infusion
Indications
- Shock with low cardiac output or distributive shock, to improve haemodynamics
- Septic shock (norepinephrine is usually preferred) Sepsis and septic shock →
Adverse effects
Common
- Tachycardia and palpitations
- Ectopic beats and other arrhythmias
- Nausea, vomiting and headache
- Angina
- Local vasoconstriction at the infusion site
Contraindications
- Pheochromocytoma
Key interactions
- MAO inhibitors
- Dopamine is not broken down: severe hypertension and arrhythmias
- Tricyclic antidepressants
- Stronger pressor response; blood pressure is watched
- Halogenated anaesthetics
- Sensitised myocardium: ventricular arrhythmias and hypertension
- Other vasopressors and oxytocic drugs
- Severe hypertension
What is monitored
- Continuous blood pressure, heart rate and ECG
- Urine output and peripheral perfusion
- Infusion site for blanching or extravasation
Administration and safety
- Always diluted and given by infusion pump into a large vein, preferably central, in an intensive care setting.
- Check the solution before use: do not use it if it is darker than slightly yellow or discoloured.
- Do not add other medicines to the dopamine infusion.
- Extravasation is an emergency: stop the infusion at that site and infiltrate phentolamine as early as possible.
- Dopamine and dobutamine have look-alike names: read the label twice.
Nursing care
- Before: confirm that hypovolaemia, acidosis and hypoxia have been corrected.
- During: blood pressure, heart rate and rhythm continuously; urine output hourly.
- Check colour, temperature and capillary refill of the extremities and the infusion site often.
- Wean gradually while blood volume is maintained; abrupt stopping can cause marked hypotension.
Pregnancy and breastfeeding
There are no human data; shock itself threatens the mother and the fetus, so treatment is not delayed. With oxytocic drugs it can cause severe maternal hypertension.
Test yourself
Think of the answer, then tap the question to see it.
In what order does dopamine activate receptors as its dose rises?
Dopamine receptors first (renal and splanchnic vasodilation), then cardiac beta-1 receptors, then vascular alpha-1 receptors (vasoconstriction).
Which tumour is a contraindication to dopamine?
Pheochromocytoma: the tumour already releases catecholamines, and dopamine could trigger a hypertensive crisis.
Why is a patient who recently took an MAO inhibitor at risk with dopamine?
MAO breaks dopamine down; with the enzyme blocked, its effect is prolonged and intensified, with severe hypertension and arrhythmias.
What is done first if a dopamine infusion extravasates?
The infusion at that site is stopped and phentolamine is infiltrated into the area as early as possible to prevent necrosis.
Related drugs
Related conditions
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Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: DailyMed - DOPAMINE HYDROCHLORIDE injection, solution, concentrate (DailyMed (U.S. National Library of Medicine), 2026); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026); eEML - Electronic Essential Medicines List (World Health Organization, 2025); Farmacología básica y clínica (Katzung), cap. 9 (McGraw Hill, 2025).
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Representative model, for educational purposes only.