Which agent is used to treat extravasation of IV alpha-adrenergic drugs such as dopamine?

• A. Hyaluronidase
• B. Normal saline
• C. Phentolamine
• D. Dextrose

Answer: (C)

Vasoconstriction from IV alpha-adrenergic drugs like dopamine can cause tissue ischemia if the drug extravasates into surrounding tissue. The treatment of choice is phentolamine, a reversible alpha-adrenergic antagonist. By blocking alpha-1 receptors in the affected area, phentolamine reverses the vasoconstriction, dilates the local vessels, and restores blood flow to limit injury. It is given by subcutaneous infiltration around the extravasation site as soon as possible, often after stopping the infusion, aspirating residual drug, and removing the cannula. Supportive measures include elevating the limb and applying warmth to promote perfusion, with careful monitoring for systemic effects such as hypotension.

Hyaluronidase is not the standard antidote for vasopressor extravasation, though it may be used in other extravasation scenarios to facilitate diffusion of certain infiltrated drugs. Normal saline or dextrose are not antidotes for this issue and do not reverse the local vasoconstriction.