Question

A nurse is preparing to administer phenobarbital 3 mg/kg P0 twice a day to a school-age child who weighs 44 lb. Available is phenobarbital elixir 20 mg/5 mL. How many mL should the nurse plan to administer per dose? (Round the answer to the nearest whole number. Use a leading zero if it applies. Do not use a trailing zero.)

A. 5 mL
B. 6 mL
C. 7 mL
D. 8 mL

Answer 1

To calculate the mL of phenobarbital elixir that should be administered per dose, we need to convert the child's weight from lb to kg, calculate the total dose based on the dosage, and then determine the mL based on the concentration of the elixir.

Step-by-step explanation:

To determine how many mL of phenobarbital elixir should be administered per dose, we need to calculate the child's weight in kg first. The weight of the child is given as 44 lb. To convert this to kg, we can use the conversion factor 1 kg = 2.2 lb. So, the weight of the child in kg is 44 lb / 2.2 lb/kg = 20 kg.

Next, we can calculate the total dose of phenobarbital using the dosage of 3 mg/kg and the weight of the child:

Total dose = 3 mg/kg x 20 kg = 60 mg.

Finally, we can determine how many mL of the elixir need to be administered to deliver a dose of 60 mg. The elixir has a concentration of 20 mg/5 mL, so:

Ml per dose = (60 mg x 5 mL) / 20 mg = 15 mL.

Therefore, the nurse should plan to administer 15 mL per dose.