Final answer:
The child is receiving approximately 44.44 mg/kg/24 h of Keflex, which falls within the recommended dosage range and does not exceed the maximum allowed daily limit of 2 g/24 h.
Step-by-step explanation:
The physician orders Keflex 500 mg orally every 6 hours (q6 h) for a 99-lb school-age child.
To convert the child's weight from pounds to kilograms, we use the conversion factor: 1 kilogram equals approximately 2.2 pounds. Therefore, 99 lb divided by 2.2 gives us approximately 45 kilograms (99 / 2.2 = 45 kg).
The child is receiving 500 mg of Keflex every 6 hours.
Since there are four 6-hour periods in 24 hours, the total daily dose is 500 mg multiplied by 4, which equals 2000 mg (2 g).
We calculate the dosage per kilogram by dividing the total daily dose of Keflex (in mg) by the child's weight in kilograms.
Therefore, 2000 mg divided by 45 kg equals approximately 44.44 mg/kg/24 h.
This calculation confirms that the dosage the child is receiving is within the recommended daily oral dosage range of 50 to 100 mg/kg/24 h divided q6 h.
Moreover, it is important to note that the maximum dosage should not exceed 2 g/24 h, and this prescribed dose is at the upper limit.