What is the appropriate ibuprofen dose for a 5‑year‑old child weighing 38 lb (≈17 kg)?

Ibuprofen Dosing for a 38 lb (17 kg) 5-Year-Old Child

For a 5-year-old child weighing 38 lb (17 kg), administer ibuprofen 170 mg per dose (10 mg/kg), which can be practically rounded to 160–200 mg depending on available formulation strengths, given every 6–8 hours as needed, not to exceed 3 doses in 24 hours. 1, 2

Weight-Based Calculation

• The standard pediatric ibuprofen dose is 10 mg/kg per dose for children in this age and weight range 1, 2
• For a child weighing 17 kg: 17 kg × 10 mg/kg = 170 mg per dose 1
• This calculated dose can be rounded to a practical 160–200 mg based on available tablet or liquid formulation strengths (e.g., children's ibuprofen suspension typically comes in 100 mg/5 mL concentration) 1

Dosing Schedule and Maximum Limits

• Administer every 6–8 hours (or every 8 hours for more conservative dosing), with a maximum of 3 doses in 24 hours 1, 2
• The maximum daily dose must not exceed 40 mg/kg/day, which equals approximately 680 mg/day for this 17 kg child 1, 2
• At the recommended 170 mg per dose given three times daily, the total daily dose would be 510 mg/day, which is well below the maximum threshold 1

Route of Administration

• Oral administration is the preferred and standard route for outpatient pediatric pain and fever management 1
• Oral syrup/suspension is preferred over other formulations due to more rapid and consistent absorption in young children 2

Clinical Context and Efficacy

• Ibuprofen is effective for treating acute pain and fever in children, with maximum temperature reduction occurring 3–4 hours after administration 3
• The effective dose range has been established as 7.5–10 mg/kg in clinical trials, with the 10 mg/kg dose providing optimal efficacy 3
• Ibuprofen has been shown to be equally or more effective than acetaminophen as an antipyretic and analgesic, with a longer duration of action 3, 4

Critical Safety Considerations

• Never exceed the maximum daily dose of 40 mg/kg/day (680 mg/day for this child) 2
• Counsel parents to avoid all other products containing ibuprofen or other NSAIDs to prevent inadvertent overdose or combination toxicity 2
• Ibuprofen is not recommended for infants under 6 months of age; for younger infants, acetaminophen is the only recommended analgesic 2

Common Pitfalls to Avoid

• Parents frequently misdose antipyretics, with studies showing 51% of caregivers give inaccurate doses, particularly to infants 5
• Weight-based dosing is more accurate than age-based dosing; caregivers who base dosing on weight are significantly less likely to misdose medication 5
• Be aware of "hidden sources" of NSAIDs in combination over-the-counter medications that parents may be giving simultaneously 1
• Do not combine ibuprofen with other NSAIDs without dose adjustment, as this provides no additional benefit but significantly increases adverse effects 1

Alternative or Combination Therapy

• If breakthrough fever or pain occurs, acetaminophen (paracetamol) can be alternated with ibuprofen by staggering administration times: give acetaminophen 10–15 mg/kg every 4–6 hours and ibuprofen 10 mg/kg every 6–8 hours, alternating between the two every 3–4 hours 2
• The combination of ibuprofen and acetaminophen is more effective than single-agent use alone for moderate to severe pain, though this approach requires careful parent education to prevent dosing errors 2