Final answer:
The child will receive a dosage of 1.8375 mg per dose of codeine based on their body surface area (BSA) and the prescribed dosage of 15 mg/m2/day.
Step-by-step explanation:
The child's BSA is 0.49 m2. To calculate the daily dose of codeine, we need to multiply the BSA by the prescribed dosage, which is 15 mg/m2/day.
The child is prescribed codeine 15 mg/m2/day, to be given every 6 hours as needed (PRN) for pain. The child has a body surface area (BSA) of 0.49 m2. First, we calculate the total daily dose by multiplying the dose per m2 by the child's BSA. This gives us 15 mg/m2/day × 0.49 m2, which equals 7.35 mg/day. To find the per dose amount, we divide this by the number of doses per day, which is 4 (as the medicine is to be given every 6 hours, and there are 24 hours in a day). So, 7.35 mg/day ÷ 4 doses/day equals approximately 1.84 mg/dose. However, since it is impractical to measure out 1.84 mg, the actual dose administered may need to be rounded to a practical amount like 2 mg when the medication is dispensed.
Daily dose = BSA x dosage
Daily dose = 0.49 m2 x 15 mg/m2/day = 7.35 mg/day
Since the medication is administered every 6 hours as needed (PRN), we can divide the daily dose by 4 to find the dosage per dose.
Dosage per dose = daily dose / 4 = 7.35 mg/day / 4 = 1.8375 mg/dose
Therefore, the mg per dose is 1.8375.