Dopamine

Dopamine is a second line drug for symptomatic bradycardia, and should be used after atropine. It is also used for hypotension, which is a systolic blood pressure of less than or equal to 100 mm Hg with signs and symptoms of shock.

Dopamine is a neurotransmitter, which causes constriction of blood vessels, increase in heart rate, and increase in the heart’s contraction force. At doses of 5 to 10 mcg /kg/minute, it is a positive inotrope and chronotrope. At this dose, called a cardiac dose, dopamine acts on the sympathetic nervous system to increase cardiac output and blood pressure.

At a pressor dose of 10 to 20 mcg/kg/minute, dopamine has a strong effect on the blood vessels, causing vasoconstriction to increase blood pressure. However, at this dose, it may also cause worsening renal function and cardiac arrhythmias.

Dosage

Dopamine is given IV at an infusion rate of 2 to 20 mcg/kg/minute.

Cardiac dose: 5 to 10 mcg/kg/min.

Pressor dose 10-20 mcg/kg/min.

Contraindications

Do not mix with sodium bicarbonate.

Precautions