Question

A nurse is preparing to administer phenobarbital to a toddler who has a seizure disorder and weighs 10 kg (22 lb). The prescription reads phenobarbital sodium 2.5 mg/kg PO BID. Available is phenobarbital 20 mg/5 mL. How many mL should the nurse administer with each dose? (Round to the nearest hundredth)

Answer 1

The nurse should administer 1.25 mL of phenobarbital with each dose.

Step-by-step explanation:

To find the mL of phenobarbital to administer, you will first calculate the total amount of phenobarbital needed for each dose. The prescription states a dosage of 2.5 mg/kg, and the toddler weighs 10 kg, so the total amount needed is 2.5 mg/kg x 10 kg = 25 mg. Next, you will calculate the mL needed based on the concentration of the phenobarbital available. The phenobarbital is available as 20 mg/5 mL, so you can set up a proportion to find the mL needed: 20 mg/5 mL = 25 mg/x mL. Cross-multiply and solve for x, the mL needed: 20 mg * x mL = 25 mg * 5 mL. Divide both sides by 20 mg to isolate x: x mL = (25 mg * 5 mL) / 20 mg. Simplify: x mL = 1.25 mL. Therefore, the nurse should administer 1.25 mL of phenobarbital with each dose.