What is the typical dosage of dopamine (dopamine hydrochloride) in normal saline (0.9% sodium chloride solution) for intravenous administration?

Dopamine Infusion Preparation and Dosing

Dopamine should be prepared using the "rule of 6" for weight-based dosing: 0.6 × body weight (kg) = number of milligrams diluted to total 100 mL of normal saline, where 1 mL/hr then delivers 0.1 mcg/kg/min. 1

Standard Preparation Methods

Rule of 6 (Preferred for Pediatrics and Weight-Based Dosing)

• Multiply 0.6 × patient's weight in kg = mg of dopamine 1
• Dilute this amount to a total volume of 100 mL normal saline 1
• Infusion rate: 1 mL/hr = 0.1 mcg/kg/min 1
• This method allows direct conversion where the infusion rate in mL/hr equals the dose in mcg/kg/min × 10 1

Standard Adult Concentrations

• 400 mg dopamine in 500 mL D5W (800 mcg/mL) - most common concentration 1, 2
• 800 mg dopamine in 500 mL D5W (1600 mcg/mL) - for fluid-restricted patients 1, 2
• 1600 mg dopamine in 500 mL D5W (3200 mcg/mL) - for severe fluid restriction 1, 2

Dosing Guidelines

Initial Dosing

• Start at 2-5 mcg/kg/min for most patients 1, 2
• This initial range provides dopaminergic and mild β-adrenergic effects 1

Dose-Dependent Effects

• 2-3 mcg/kg/min: Predominantly dopaminergic receptor stimulation causing renal and mesenteric vasodilation 1
• 3-5 mcg/kg/min: β-adrenergic effects with increased cardiac contractility and cardiac output 1
• >5-10 mcg/kg/min: Progressive α-adrenergic stimulation leading to peripheral vasoconstriction 1

Titration Strategy

• Increase in 5-10 mcg/kg/min increments up to 20-50 mcg/kg/min as needed 2
• Target: Systolic blood pressure >90 mmHg (or age-appropriate target) 1
• Maximum effective dose: 20 mcg/kg/min - doses exceeding this may cause excessive vasoconstriction 1, 2
• If >50 mcg/kg/min required: Check urine output frequently and consider alternative vasopressors 2

Critical Administration Requirements

Infusion Method

• Use only an infusion pump, preferably volumetric - never rely on gravity drip 2
• Infuse into a large vein (antecubital fossa preferred over hand/ankle veins) to prevent extravasation 2
• Avoid umbilical artery catheter administration 2

Solution Preparation Precautions

• Cover bottle/syringe with protective foil to prevent light-induced breakdown 1
• Do NOT add sodium bicarbonate or alkaline solutions - dopamine is inactivated in alkaline pH 2
• Do NOT use if solution is darker than slightly yellow 2
• Dopamine remains stable in normal saline or dextrose solutions for up to 84 hours 3

Monitoring Requirements

• Continuous blood pressure monitoring, preferably with arterial line 1
• Continuous ECG monitoring 1
• Assess peripheral perfusion regularly 1
• Monitor urine output - decreasing flow despite adequate BP warrants dose reduction 2

Extravasation Management

If extravasation occurs, immediately inject phentolamine 0.1-0.2 mg/kg (up to 10 mg) diluted in 10 mL of 0.9% sodium chloride intradermally at the site to prevent tissue necrosis. 1

Common Pitfalls to Avoid

• Excessive vasoconstriction: Manifests as disproportionate rise in diastolic pressure with decreased pulse pressure - reduce infusion rate immediately 2
• Tachyarrhythmias: Development of new dysrhythmias or increasing tachycardia warrants dose reduction or temporary suspension 2
• Inadequate volume resuscitation: Ensure adequate fluid resuscitation before initiating dopamine 1
• Low-dose dopamine for renal protection: There is no justification for using low-dose dopamine (<5 mcg/kg/min) for renal protection in critically ill patients, as it provides no clinically significant benefit and may worsen outcomes 4

Special Considerations

• In decompensated shock or marked circulatory instability: Epinephrine or norepinephrine may be preferable to dopamine 1
• Interindividual variability: Plasma dopamine concentrations can vary 10- to 75-fold between patients receiving identical weight-based doses, necessitating careful titration to clinical effect rather than fixed dosing 5
• Discontinuation: Gradually decrease dose while expanding blood volume with IV fluids to prevent marked hypotension 2