Dopamine

Question 1

Class

Answer 1

Sympathomimetic, inotropic agent

Question 2

MOA

Answer 2

Stimulates alpha, beta, and dopaminergic receptors in a dose dependent fashion. Increases systemic vascular resistance. Causes peripheral vasoconstriction, but dilates renal, mesenteric and cerebral vasculature at low doses. Increases inotropic and chronotropic effects on the heart.

Question 3

Indications

Answer 3

Cardiogenic shock. Distributive shock – septic, spinal, anaphylaxis (Anaphylaxis refractory to epinephrine and fluid boluses). Hypotension with low cardiac output states. Bradycardia refractory to atropine and pacing. Crush injuries.

Question 4

Contraindications

Answer 4

Hypovolemic shock, pheochromocytoma, tachyarrhythmias, v-fib

Question 5

Adverse reactions

Answer 5

Cardiac arrhythmias- tachycardias, hypertension, increased myocardial oxygen demand; extravasation may cause tissue necrosis

Question 6

Drug Interactions

Answer 6

Incompatible with alkaline solutions. MAOIs will enhance the effects of dopamine. Bretylium may potentiate effect of dopamine. Beta-blockers may antagonize the effects of dopamine. When administered with phenytoin; may cause hypotension, bradycardia, and seizures

Question 7

Dosage

Answer 7

Adult: IV infusion at 2 – 20 mcg/kg/min titrated to effect
400 mg in 250 ml (or 800mg/500ml or 1600mg/1000mL)

Pediatric: 2 – 20 mcg/kg/min titrated to effect

Question 8

Duration

Answer 8

Onset: 1 – 4 minutes
Peak effects: 5 – 10 minutes
Duration: Effects stop almost immediately after infusion is stopped

Question 9

Special Considerations

Answer 9

Effects are dose dependent
 1 - 2 mcg/kg/min: dilates vessels in kidneys; increased urine output.
 5 – 10 mcg/kg/min: increased heart rate (beta effects)
 10 – 20 mcg/kg/min: primarily vasoconstriction (alpha effects)
Extravasation will cause tissue necrosis and sloughing.
Abrupt termination may cause acute hypotension, discontinue gradually.

Question 10

Pregnancy category

Answer 10

C

Question 11

Supplied

Answer 11

400 mg in 5 mL, MUST be added to 250 mL bag normal saline to make 1600mcg/mL. Premixed bag 800 mg in 500 mL