A nurse practitioner prepares an injection of promethazine, an antihistamine used to treat allergic rhinitis. If the stock bottle is labeled 30.mg/mL and the order is a dose of 10.0mg, how many milliliters will the nurse draw up in the syringe?
With a dose order of 10mg and the stock bottle being labeled 30mg/mL, the nurse will need to draw up .33mL. We come to this answer by taking the dose order of 10mg and multiplying by the stock bottle amount of 1mL/30mg. The 30mg/mL was inverted to account for units so that mg cancels out and we are left with mL answer. Total mL needed = 10mg * (1mL/30mg) = .33mL
