Dopamine Injection: Administration Guide

1. Preparation and Dilution

• Available as dopamine HCl injection, commonly 40 mg/mL (5- or 10-mL vials), for further dilution.
• Standard dilution: add 200-400 mg dopamine to 250-500 mL of a compatible IV fluid (D5W, normal saline, lactated Ringer's, D5/NS, D5/LR), giving a typical concentration of 0.8-1.6 mg/mL (up to 3.2 mg/mL if fluid restriction is needed).
• Inspect the solution before use - it should be clear and colorless to slightly yellow. Discard if darker, brown, pink, or purple, as this indicates decomposition.
• Diluted solution is stable for 24 hours.

2. Route and Site

• Give into a large vein (antecubital fossa or central line preferred) via infusion pump.
• Avoid small peripheral veins, particularly on the hand or wrist - dopamine is a potent vasoconstrictor and extravasation can cause tissue necrosis/sloughing.
• Continuously monitor the infusion site; if extravasation occurs, the antidote is local infiltration of phentolamine.

3. Dosing (weight-based, titrated to effect)

• 0.5-2 mcg/kg/min ("renal dose"): dopaminergic receptors, mild increase in renal/mesenteric blood flow (this indication is now largely abandoned - see caveat below)
• 2-10 mcg/kg/min (beta-1 dominant): increased cardiac contractility, heart rate, cardiac output - used in cardiogenic shock/heart failure
• >10-20 mcg/kg/min (alpha dominant): vasoconstriction, increased blood pressure - used in refractory hypotension/septic shock, with increasing arrhythmia risk

4. Monitoring

• Continuous ECG, blood pressure (ideally arterial line), and heart rate monitoring.
• Watch for tachyarrhythmias, ectopy, and excessive vasoconstriction (cool extremities, decreased urine output) at higher doses.
• Correct hypovolemia before or during initiation - dopamine is not a substitute for volume resuscitation.

5. Discontinuation

• Taper gradually rather than stopping abruptly, since abrupt cessation can cause rebound hypotension.

Special notes

• In children, particularly with cardiac arrest/shock, epinephrine is often preferred over dopamine because dopamine's action depends on releasing endogenous norepinephrine stores, which may be depleted in critically ill children - Tintinalli's Emergency Medicine. Pediatric infusion range in congenital heart failure is typically 5-15 mcg/kg/min - Tintinalli's Emergency Medicine.
• Low-dose "renal-protective" dopamine (1-5 mcg/kg/min) was historically used to augment urine output/renal perfusion, but current evidence does not support a meaningful renal-protective benefit, and this practice has fallen out of favor in modern critical care.
• Oral or other slow-release routes are not effective - dopamine has a very short plasma half-life (about 1-5 minutes), which is why it must be given as a continuous infusion.