From the Guidelines
Dopamine is a neurotransmitter that plays a crucial role in the brain and body, primarily affecting movement control, emotional responses, and the brain's pleasure and reward systems. The function of dopamine is multifaceted, and it helps regulate motivation, allowing us to experience feelings of pleasure, satisfaction, and reinforcement when we take actions that serve our needs 1. In the brain's motor system, dopamine helps control smooth, purposeful muscle activity and movement. When dopamine levels are too low, as in Parkinson's disease, movement becomes difficult and tremors may develop. Beyond movement and pleasure, dopamine also influences attention, learning, mood regulation, sleep patterns, and even kidney function.
Some of the key effects of dopamine include:
- Producing direct dopaminergic effects and indirect β- and α-adrenergic effects through stimulation of norepinephrine release 1
- Increasing oxygen consumption, but not necessarily improving blood pressure or cardiac output in certain patient populations 1
- Having potential benefits in patients with compromised systolic function, but also causing more tachycardia and potentially being more arrhythmogenic than norepinephrine 1
- Not being recommended as a first-line treatment for septic shock, due to its association with increased risk of short-term mortality and arrhythmias compared to norepinephrine 1
In clinical practice, dopamine should be used with caution and only when necessary, due to its potential risks and side effects. The body produces dopamine naturally, but certain medications can either increase dopamine levels or mimic its effects to treat conditions like Parkinson's disease, ADHD, and some psychiatric disorders. Understanding dopamine's function helps explain why activities that trigger its release (like eating, sex, or achieving goals) feel rewarding and why dopamine-related disorders can affect both physical movement and emotional well-being.
From the FDA Drug Label
Dopamine administered intravenously is a myocardial inotropic agent, which also may increase mesenteric and renal blood flow plus urinary output. Dopamine (also referred to as 3-hydroxytyramine) is a naturally occurring endogenous catecholamine precursor of norepinephrine.
The function of dopamine is to act as a myocardial inotropic agent, increasing mesenteric and renal blood flow and urinary output. It is also a naturally occurring endogenous catecholamine and a precursor of norepinephrine 2.
From the Research
Function of Dopamine
The function of dopamine is a complex topic that has been studied in various contexts.
- Dopamine is a critical modulator of both learning and motivation 3.
- It conveys motivational value and promotes movement even on subsecond timescales 3.
- Dopamine release related to motivation is rapidly and locally sculpted by receptors on dopamine terminals, independently from dopamine cell firing 3.
- In the context of shock treatment, dopamine is used as a first-line vasopressor agent to restore and maintain blood pressure 4, 5.
- However, the use of dopamine in this context has been associated with a greater number of adverse events, such as arrhythmic events, compared to norepinephrine 4, 5, 6.
Dopamine in Cardiogenic Shock
- In cardiogenic shock, dopamine has been compared to norepinephrine as a first-line vasopressor agent 5, 6.
- Studies have shown that norepinephrine may be associated with improved outcomes, such as lower 28-day mortality and fewer arrhythmic events, compared to dopamine 5, 6.
- However, other studies have found no significant difference in outcomes between dopamine and norepinephrine in cardiogenic shock 5.
Dopamine's Role in the Body
- Dopamine provides a dynamic estimate of whether it is worth expending a limited internal resource, such as energy, attention, or time 3.
- The behavioral impact of dopamine varies by subregion, but it plays a critical role in regulating ongoing behavior 3.
- Dopamine is involved in various physiological processes, including movement, motivation, and learning 3.