Pediatric Dosage Calculation Practice Questions

72 questions in this topic · free · worked solutions included

Weight-based pediatric orders, suspension volumes from label concentrations, safe-range checks, BSA (mg/m²) dosing and maintenance fluids by the 100-50-20 rule.

Pediatric questions add a conversion step (lb→kg) on purpose — the trap is built in.

Try 10 practice questions

Q1. Order: Amoxicillin 40 mg/kg/day PO divided q8h. Child weighs 18 kg.

How many mg per dose? (Round to 1 decimal if needed)

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Answer: 240 mg

1Daily total: 40 × 18 = 720 mg/day
2Doses per day: q8h → 3 doses
3Divide: 720 ÷ 3 = 240 mg
⚠ Common mistake: Treating the mg/kg/day order as a per-dose order.

Q2. Order: Cephalexin 50 mg/kg/day PO divided q6h. Child weighs 22 kg.

How many mg per dose? (Round to 1 decimal if needed)

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Answer: 275 mg

1Daily total: 50 × 22 = 1,100 mg/day
2Doses per day: q6h → 4 doses
3Divide: 1,100 ÷ 4 = 275 mg
⚠ Common mistake: Treating the mg/kg/day order as a per-dose order.

Q3. Order: Amoxicillin 45 mg/kg/day PO divided q12h. Child weighs 16 kg.

How many mg per dose? (Round to 1 decimal if needed)

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Answer: 360 mg

1Daily total: 45 × 16 = 720 mg/day
2Doses per day: q12h → 2 doses
3Divide: 720 ÷ 2 = 360 mg
⚠ Common mistake: Treating the mg/kg/day order as a per-dose order.

Q4. Order: Azithromycin 10 mg/kg/day PO divided q24h. Child weighs 25 kg.

How many mg per dose? (Round to 1 decimal if needed)

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Answer: 250 mg

1Daily total: 10 × 25 = 250 mg/day
2Doses per day: q24h → 1 dose
3Divide: 250 ÷ 1 = 250 mg
⚠ Common mistake: Treating the mg/kg/day order as a per-dose order.

Q5. Order: Cefdinir 14 mg/kg/day PO divided q24h. Child weighs 20 kg.

How many mg per dose? (Round to 1 decimal if needed)

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Answer: 280 mg

1Daily total: 14 × 20 = 280 mg/day
2Doses per day: q24h → 1 dose
3Divide: 280 ÷ 1 = 280 mg
⚠ Common mistake: Treating the mg/kg/day order as a per-dose order.

Q6. Order: Amoxicillin 90 mg/kg/day PO divided q12h. Child weighs 14 kg.

How many mg per dose? (Round to 1 decimal if needed)

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Answer: 630 mg

1Daily total: 90 × 14 = 1,260 mg/day
2Doses per day: q12h → 2 doses
3Divide: 1,260 ÷ 2 = 630 mg
⚠ Common mistake: Treating the mg/kg/day order as a per-dose order.

Q7. Order: Cephalexin 25 mg/kg/day PO divided q6h. Child weighs 30 kg.

How many mg per dose? (Round to 1 decimal if needed)

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Answer: 187.5 mg

1Daily total: 25 × 30 = 750 mg/day
2Doses per day: q6h → 4 doses
3Divide: 750 ÷ 4 = 187.5 mg
⚠ Common mistake: Treating the mg/kg/day order as a per-dose order.

Q8. Order: Clindamycin 20 mg/kg/day PO divided q8h. Child weighs 24 kg.

How many mg per dose? (Round to 1 decimal if needed)

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Answer: 160 mg

1Daily total: 20 × 24 = 480 mg/day
2Doses per day: q8h → 3 doses
3Divide: 480 ÷ 3 = 160 mg
⚠ Common mistake: Treating the mg/kg/day order as a per-dose order.

Q9. Order: Amoxicillin 50 mg/kg/day PO divided q8h. Child weighs 12 kg.

How many mg per dose? (Round to 1 decimal if needed)

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Answer: 200 mg

1Daily total: 50 × 12 = 600 mg/day
2Doses per day: q8h → 3 doses
3Divide: 600 ÷ 3 = 200 mg
⚠ Common mistake: Treating the mg/kg/day order as a per-dose order.

Q10. Order: Cefdinir 7 mg/kg/day PO divided q12h. Child weighs 28 kg.

How many mg per dose? (Round to 1 decimal if needed)

Show answer & worked solution

Answer: 98 mg

1Daily total: 7 × 28 = 196 mg/day
2Doses per day: q12h → 2 doses
3Divide: 196 ÷ 2 = 98 mg
⚠ Common mistake: Treating the mg/kg/day order as a per-dose order.

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