Pediatric Dosage
Calculations (Mg/Kg)
Calculate safe medication doses for children using weight: \( \text{dose} = \text{mg/kg} \times \text{weight} \). A core NCLEX-RN skill.
Why Dose by Body Weight?
Children are not small adults. Their organ systems, metabolism, and body composition differ greatly. A fixed adult dose could easily be a toxic overdose for a small child.
Key Terms
First: Convert Pounds to Kg
The Core Formula
Dividing into Doses
Safe Range vs. Ordered Dose
A critical NCLEX skill: verify the order is safe before giving it. Compare what was ordered against the calculated safe range.
Step-by-Step Approach
Worked Example 1
A child weighs 20 kg. The order is amoxicillin 25 mg/kg/day divided q8h. What is each dose?
Worked Example 2
A child weighs 44 lb. Order: acetaminophen 15 mg/kg per dose. Available: \( 160 \text{ mg} / 5 \text{ mL} \). How many mL?
Worked Example 3: Safety Check
A child weighs 15 kg. Safe range is 10–20 mg/kg/day. The order is 360 mg/day. Is it safe?
Common Mistakes
Quick Reference
| Formula | Example | |
|---|---|---|
| lb → kg | \( \text{lb} \div 2.2 \) | \( 22 \div 2.2 = 10 \) |
| Daily Dose | \( \text{mg/kg} \times \text{kg} \) | \( 10 \times 10 = 100 \) |
| Each Dose | \( \text{daily} \div \text{doses} \) | \( 100 \div 2 = 50 \) |
| Volume | \( \dfrac{\text{dose}}{\text{avail}} \times \text{mL} \) | \( \dfrac{50}{25} \times 5 = 10 \) |
Before You Administer
Now test your understanding with 5 practice questions.
Question 1 of 5
A child weighs 66 lb. What is the weight in kg?
Question 2 of 5
A 25 kg child is ordered 10 mg/kg/day. What is the total daily dose?
Question 3 of 5
A daily dose of 600 mg is divided q6h. How much is each dose?
Question 4 of 5
Order: 200 mg. Available: \( 250 \text{ mg} / 5 \text{ mL} \). How many mL?
Question 5 of 5
A 10 kg child has a safe max of 15 mg/kg/day. The order is 180 mg/day. What should the nurse do?