Dopamine, sold under the brand name Intropin among others, is a medication most commonly used in the treatment of very low blood pressure, a slow heart rate that is causing symptoms, and, if epinephrine is not available, cardiac arrest.[4] In newborn babies it continues to be the preferred treatment for very low blood pressure.[5] In children epinephrine or norepinephrine is generally preferred while in adults norepinephrine is generally preferred for very low blood pressure.[6][7] It is given intravenously or intraosseously as a continuous infusion.[4] Effects typically begin within five minutes.[4] Doses are then increased to effect.[4]
Common side effects include worsening kidney function, an irregular heartbeat, chest pain, vomiting, headache, or anxiety.[4] If it enters into the soft tissue around the vein local tissue death may occur.[4] The medication phentolamine can be given to try to decrease this risk.[4] It is unclear if dopamine is safe to use during pregnancy or breastfeeding.[4] At low doses dopamine mainly triggers dopamine receptors and β1-adrenergic receptors while at high doses it works via α-adrenergic receptors.[4]
Dopamine was first synthesized in a laboratory in 1910 by George Barger and James Ewens in England.[8] It is on the World Health Organization's List of Essential Medicines.[9] In human physiology dopamine is a neurotransmitter as well as a hormone.[10]
In newborn babies it continues to be the preferred treatment for very low blood pressure.[5] In children epinephrine or norepinephrine is generally preferred while in adults norepinephrine is generally preferred for very low blood pressure.[6][7]
In those with low blood volume or septic shock, this should be corrected with intravenous fluids before dopamine is considered.[4]
Low-dosage dopamine has been routinely used for the treatment and prevention of acute kidney injury. However, since 1999 a number of reviews have concluded that doses at such low levels are not effective and may sometimes be harmful.[11][12]
Since the half-life of dopamine in plasma is short—approximately one minute in adults, two minutes in newborn babies and up to five minutes in preterm babies—it is usually given as a continuous intravenous drip rather than a single injection.[13]
A fluorinated form of L-DOPA known as fluorodopa is available for use in positron emission tomography to assess the function of the nigrostriatal pathway.[14]
Dopamine should generally not be given to people who have a pheochromocytoma or uncorrected very fast heart rate.[4]
The LD50, or dose which is expected to prove lethal in 50% of the population, has been found to be: 59 mg/kg (mouse; administered intravenously); 950 mg/kg (mouse; administered intraperitoneally); 163 mg/kg (rat; administered intraperitoneally); 79 mg/kg (dog; administered intravenously).[15]
If extravasation occurs local tissue death may result.[4] The medication phentolamine can be injected at the site to try to decrease the risk of tissue death.[4]
Its effects, depending on dosage, include an increase in sodium excretion by the kidneys, an increase in urine output, an increase in heart rate, and an increase in blood pressure.[13] At low doses it acts through the sympathetic nervous system to increase heart muscle contraction force and heart rate, thereby increasing cardiac output and blood pressure.[16] Higher doses also cause vasoconstriction that further increases blood pressure.[16][17]
While some effects result from stimulation of dopamine receptors, the prominent cardiovascular effects result from dopamine acting at α1, β1, and β2 adrenergic receptors.[18][19]
In March 2024, the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) adopted a positive opinion, recommending the granting of a pediatric use marketing authorization (PUMA) for the medicinal product Neoatricon, intended for treatment of hypotension in neonates, infants and children under 18 years of age.[3][20] The applicant for this medicinal product is BrePco Biopharma Limited.[3]
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: CS1 maint: overridden setting (link)According to Hornykiewicz,6 dopamine was first synthesized by George Barger and James Ewens in 1910 at the Wellcome labs in London, England.
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: CS1 maint: overridden setting (link)Dopamine binds to alpha-1 and beta-1 adrenergic receptors. Mediated through myocardial beta-1 adrenergic receptors, dopamine increase heart rate and force, thereby increasing cardiac output. Alpha-1 adrenergic receptor stimulation on vascular smooth muscle, leads to vasoconstriction and results in an increase in systemic vascular resistance
Dopamine binds to beta-1, beta-2, alpha-1 and dopaminergic receptors.