DOPAMINE (INTROPIN)

Class

Sympathetic Agonist

Pharmacology and Actions

1. Dopamine is a chemical precursor of epinephrine. It occurs naturally in humans.
2. Dopamine has the following dose-related effects:
   1. 2-10 mcg/kg/min: beta effects on heart, usually increases cardiac output without increasing heart rate or blood pressure.
   2. 10-20 mcg/kg/min: alpha peripheral effects cause peripheral vasoconstriction and increased blood pressure.

Indications

1. Symptomatic hypotension from causes other than hypovolemia; such as cardiogenic shock, neurogenic shock, septic shock, and anaphylactic shock.

Contraindications

1. Pheochromocytoma (a tumor of the adrenal gland)

Precautions

1. Dopamine is contraindicated in hypovolemic shock.  Pressor agents worsen tissue hypoxia in the presence of hypovolemia from diuretics and poor intake, careful differentiation is necessary. Invasive monitoring is often the only way to differentiate forms of shock in the elderly, and treatment with dopamine is therefore indicated in the field only in severely unstable patients with evidence of increased venous pressure.
2. Dopamine may induce tachydysrhythmias. If the heart rate exceeds 140, the infusion should be stopped.
3. At low doses, decreased blood pressure may occur due to peripheral vasodilatation. Increasing infusion will correct this.
4. Should not be added to Sodium Bicarbonate or other alkaline solutions, since dopamine will be inactivated at higher pH.
5. Tissue extravasation at the IV site can cause skin sloughing due to vasoconstriction. Be sure to make emergency department personnel aware if there has been any extravasation of dopamine-containing solutions, so that proper treatment can be instituted.
6. Can cause hypertensive crisis in susceptible individuals.

Administration

1. The initial infusion rate is from from 5-20mcg/kg/min; expect to start at 10 mcg/kg/min this may be increased until blood pressure improves.

Side Effects and Special Notes

1. Consultation with medical control is strongly recommended with any dosage changes.
2. Dopamine can cause nervousness, headache, dysrythmias, palpitations, chest pain, dyspnea,      nausea and vomiting. Many of these effects are dose-related.