Pediatric dose calculations by body weight MCQs With Answer

Pediatric Dose Calculations by Body Weight MCQs With Answer help B. Pharm students master clinical dosing based on mg/kg, mg/kg/day, and mg/kg/dose. Accurate pediatric dosing requires understanding pharmacokinetics, therapeutic index, maximum dose caps, dosing intervals, dilution/concentration (mg/mL), and safe rounding to measurable volumes. These skills prevent underdosing and toxicity, especially for narrow-therapeutic-index drugs and special populations (neonates, obese, or renally impaired children). You will practice converting weight-based doses to milligrams and milliliters, interpreting labels (per dose vs per day), applying dose caps, and choosing actual vs adjusted body weight. Mastery of these core calculations is essential for safe dispensing and counseling in pediatric pharmacy practice. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. In pediatric prescriptions, what does “mg/kg/dose” mean?

• Milligrams per kilogram given at each administration
• Milligrams per kilogram total over 24 hours
• Milligrams per kilogram per hour for infusions
• Milligrams per kilogram per week

Correct Answer: Milligrams per kilogram given at each administration

Q2. Acetaminophen is prescribed at 15 mg/kg/dose every 6 hours. For an 18‑kg child, what is the dose per administration?

• 180 mg
• 270 mg
• 540 mg
• 75 mg

Correct Answer: 270 mg

Q3. The maximum daily acetaminophen dose is 75 mg/kg/day (not to exceed adult maximum). For a 20‑kg child, what is the weight-based daily maximum?

• 750 mg/day
• 1,000 mg/day
• 1,500 mg/day
• 2,000 mg/day

Correct Answer: 1,500 mg/day

Q4. You calculated an acetaminophen dose of 270 mg. The suspension is 160 mg/5 mL. What volume should be given per dose (round to a practical volume)?

• 8 mL
• 8.5 mL
• 9 mL
• 10 mL

Correct Answer: 8.5 mL

Q5. Ibuprofen is prescribed at 10 mg/kg/dose every 8 hours. For a 22‑kg child, how many milligrams per dose?

• 110 mg
• 220 mg
• 330 mg
• 440 mg

Correct Answer: 220 mg

Q6. Ceftriaxone 50 mg/kg IV once daily is ordered for an 18‑kg child. What is the dose?

• 500 mg
• 900 mg
• 1,000 mg
• 1,200 mg

Correct Answer: 900 mg

Q7. Gentamicin 2.5 mg/kg IV every 8 hours is prescribed for a 16‑kg child. What is the dose per administration?

• 20 mg
• 30 mg
• 40 mg
• 50 mg

Correct Answer: 40 mg

Q8. If a calculated weight-based dose exceeds the labeled maximum per dose, what is the correct action?

• Administer the calculated dose anyway
• Double-check math and still give the higher dose
• Split the high dose into two administrations immediately
• Cap the dose at the labeled maximum and do not exceed it

Correct Answer: Cap the dose at the labeled maximum and do not exceed it

Q9. For aminoglycosides in an obese child, which body weight is most appropriate for dosing?

• Total (actual) body weight
• Ideal body weight
• Adjusted body weight
• Lean body weight

Correct Answer: Adjusted body weight

Q10. Ampicillin 100 mg/kg/day divided every 6 hours is prescribed for a 24‑kg child. What is the dose per administration?

• 300 mg
• 400 mg
• 600 mg
• 1,200 mg

Correct Answer: 600 mg

Q11. Epinephrine 0.01 mg/kg of 1 mg/mL (1:1000) IM is ordered for a 25‑kg child. What volume should be given?

• 0.25 mL
• 0.30 mL
• 0.50 mL
• 1.00 mL

Correct Answer: 0.25 mL

Q12. A 55‑kg adolescent requires IM epinephrine (0.01 mg/kg, max 0.5 mg). What dose is appropriate?

• 0.55 mg (0.55 mL)
• 0.5 mg (0.5 mL)
• 0.3 mg (0.3 mL)
• 1.0 mg (1.0 mL)

Correct Answer: 0.5 mg (0.5 mL)

Q13. Vancomycin 15 mg/kg IV every 6 hours is ordered for a 20‑kg child. What is the dose per administration?

• 150 mg
• 300 mg
• 600 mg
• 750 mg

Correct Answer: 300 mg

Q14. Azithromycin is ordered as 10 mg/kg once on Day 1, then 5 mg/kg once daily for 4 days. What is the Day 1 dose for a 15‑kg child?

• 50 mg
• 100 mg
• 150 mg
• 250 mg

Correct Answer: 150 mg

Q15. The maximum daily ibuprofen dose is 40 mg/kg/day. For a 24‑kg child, what is the maximum by weight?

• 640 mg/day
• 720 mg/day
• 960 mg/day
• 1,200 mg/day

Correct Answer: 960 mg/day

Q16. Amoxicillin 45 mg/kg/day divided BID is prescribed for an 18‑kg child. Suspension is 400 mg/5 mL. What volume per dose?

• 4.0 mL
• 5.1 mL
• 5.5 mL
• 10 mL

Correct Answer: 5.1 mL

Q17. Dexamethasone 0.6 mg/kg PO once (max 10 mg) for croup in an 18‑kg child. What dose should be given?

• 10.8 mg
• 10 mg
• 8 mg
• 6 mg

Correct Answer: 10 mg

Q18. A 16‑kg child needs azithromycin 10 mg/kg once daily. Suspension is 200 mg/5 mL. What volume per dose?

• 2 mL
• 3 mL
• 4 mL
• 5 mL

Correct Answer: 4 mL

Q19. Which parameter primarily determines the weight-based loading dose for hydrophilic drugs in children?

• Clearance
• Volume of distribution
• Half-life
• Oral bioavailability

Correct Answer: Volume of distribution

Q20. The Schwartz equation in pediatrics is used mainly to:

• Calculate ideal body weight
• Estimate body surface area
• Estimate glomerular filtration rate for dose adjustment
• Convert milligrams to milliliters

Correct Answer: Estimate glomerular filtration rate for dose adjustment

Q21. A label says “30 mg/kg/day divided every 8 hours.” For a 30‑kg child, what is the dose per administration?

• 300 mg
• 900 mg
• 100 mg
• 30 mg

Correct Answer: 300 mg

Q22. Morphine 0.1 mg/kg IV is ordered for a 14‑kg child. The solution is 1 mg/mL. What volume should be given?

• 0.7 mL
• 1.0 mL
• 1.4 mL
• 2.0 mL

Correct Answer: 1.4 mL

Q23. Midazolam 0.2 mg/kg intranasal is ordered for a 17‑kg child. The solution is 5 mg/mL. What volume should be administered (rounded)?

• 0.5 mL
• 0.7 mL
• 1.0 mL
• 1.5 mL

Correct Answer: 0.7 mL

Q24. Gentamicin extended-interval dosing of 7 mg/kg IV is planned for a 30‑kg child. What is the dose?

• 140 mg
• 210 mg
• 240 mg
• 300 mg

Correct Answer: 210 mg

Q25. For underweight or malnourished children, which weight is generally used for weight-based dosing unless otherwise specified?

• Adjusted body weight
• Ideal body weight
• Actual (total) body weight
• Lean body weight

Correct Answer: Actual (total) body weight

Q26. What is the safest rounding principle for pediatric oral liquid doses?

• Always round up to ensure efficacy
• Always round down to avoid toxicity
• Round to the nearest measurable dose using the available syringe (typically 0.1–0.5 mL increments)
• Round to whole milliliters only

Correct Answer: Round to the nearest measurable dose using the available syringe (typically 0.1–0.5 mL increments)

Q27. Paracetamol 10 mg/kg/dose is ordered for a 24‑kg child. Suspension is 160 mg/5 mL. What volume per dose?

• 5 mL
• 6.25 mL
• 7.5 mL
• 10 mL

Correct Answer: 7.5 mL

Q28. For narrow-therapeutic-index drugs in children, which approach is best?

• Use adult fixed doses for simplicity
• Use fixed pediatric doses regardless of weight
• Use mg/kg dosing with therapeutic drug monitoring when available
• Use body surface area dosing for all cases

Correct Answer: Use mg/kg dosing with therapeutic drug monitoring when available

Q29. Elemental iron 3 mg/kg/day in two divided doses is prescribed for a 12‑kg child. Drops contain 15 mg/mL elemental iron. What volume per dose?

• 0.6 mL
• 1.2 mL
• 2.4 mL
• 3.0 mL

Correct Answer: 1.2 mL

Q30. If a student mistakes “mg/kg/day divided q6h” as “mg/kg/dose q6h,” the child will most likely:

• Receive half the intended daily dose
• Be overdosed by a factor equal to the number of doses per day
• Receive the correct daily dose
• Only double the intended daily dose

Correct Answer: Be overdosed by a factor equal to the number of doses per day

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