Dopamine

Dopamine: Uses, Dosage and Side Effects

Overview

• Dopamine, an endogenous catecholamine and precursor of noradrenaline, binds to dopaminergic, beta-1, and alpha-1 adrenergic receptors.

Uses of Dopamine

• Treatment of shock following correction of fluid deficiencies.
• Treatment of acute heart failure.
• Support of blood pressure during anesthesia

Dose of Dopamine in Dogs and Cats

Dogs:

• 2–10 μg (micrograms)/kg/min i.v. as a constant rate infusion; titrate to effect.
• Ensure adequate volume replacement prior to use.

Cats:

• 1–5 μg (micrograms)/kg/min i.v. as a constant rate infusion; titrate to effect.
• Ensure adequate volume replacement prior to use.

NB: in dogs and cats a CRI of 1–10 μg/kg/min i.v. will have predominantly beta-1 effects and from 10–15 μg/kg/min i.v. will have beta-1 and alpha-1 effects. Monitor closely for adverse effects during administration.

Side Effects of Dopamine in Dogs and Cats

• Dopamine extravasation results in necrosis and sloughing of surrounding tissue due to tissue ischemia.
• If extravasation occurs, use a syringe with a tiny needle to infiltrate the location with a solution of 5-10 mg phentolamine in 10-15 ml of normal saline.
• The most common side effects include nausea, vomiting, tachyarrhythmias, and blood pressure fluctuations.
• Low doses may cause hypotension, whereas high doses may cause hypertension.
• Sudden blood pressure increases can result in severe bradycardia.
• All dopamine-induced arrhythmias are best managed by discontinuing the infusion.

Contraindications of Dopamine in Dogs and Cats

• Discontinue or reduce the dose of dopamine should cardiac arrhythmias arise.

Some Notes:

• When monoamine oxidase inhibitors, doxapram, and oxytocin are used with dopamine, there is a risk of severe hypertension.
• Halothane may increase catecholamine sensitivity in the heart.
• Beta-blockers and dopamine have antagonistic effects.