A child weighs 35 lb and has an order for Keflex (cephalexin) 150 mg po every 6 hours. The literature states the usual children's dose is 25 to 50 mg/kg a day in four divided doses. The drug label reads 125 mg/5 mL. What is the safe dosage range per day for this medication?
A) 197.75 to 695.75
B) 297.75 to 725.5
C) 397.75 to 795.5
D) 400.25 to 810.75

Question

Quizplus · Accepted Answer

First, use the equivalent: 1 kg = 2.2 lb. Convert pounds to kilograms by dividing the number of pounds by 2.2: 35/2.2 = 15.909. Round to the nearest hundredths: 15.91 kg. Determine the safe dosage range. The literature states that the dose should range from 25 to 50 mg/kg, given in four divided doses. Lower range: 25 mg * 15.91 kg = 397.75 mg per day/4 doses = 99.44 mg per dose. Higher range: 50 mg *15.91 kg = 795.5 mg/4 doses = 198.88 mg per dose. The dosage ordered falls within the range that is safe: 150 mg * 4 doses (24 hours ÷ 6 = 4 doses) = 600 mg. Therefore, 600 mg falls within the daily range of 397.75 to 795.5 mg. This order is in the safe range per dose and per day.

A Child Weighs 35 Lb and Has an Order for Keflex