Question

A school-age child who weighs 42 pounds receives a post-tonsillectomy prescription for promethazine (Phenergan) 0.5 mg/kg IM to prevent postoperative nausea. The medication is available in 25 mg/ml ampules. How many ml should the nurse administer? (Enter numeric value only. If rounding is required, round to the nearest tenth).

Answer 1

To administer the correct dosage of promethazine (Phenergan) to the child, the nurse should administer approximately 0.4 ml of the medication.

Step-by-step explanation:

To calculate the amount of promethazine (Phenergan) to administer to the school-age child, we first need to find the child's weight in kilograms. To do this, we divide the weight in pounds by 2.2. So, 42 pounds is approximately 19.1 kilograms. Next, we multiply the weight in kilograms by the prescribed dosage of promethazine, which is 0.5 mg/kg. So, 19.1 kg multiplied by 0.5 mg/kg equals 9.55 mg.

Now, we need to convert milligrams to milliliters, since the medication is available in 25 mg/ml ampules. To do this, we divide 9.55 mg by 25 mg/ml, which gives us 0.382 ml. Since the question asks us to round to the nearest tenth, the nurse should administer approximately 0.4 ml of the medication to the child.