13. A hospital pharmacist is asked to prepare an intravenous infusion of dopamine. Based on the patient’s weight, the pharmacist calculates a dose of 500 mcg/min for continuous infusion. The concentration of a premixed dopamine infusion is 400 mg/250 mL. What is the concentration of the infusion on a mcg/mL basis? How many milligrams of dopamine is the patient to receive in the first hour of treatment? How long will the infusion last?​