What is the recommended dose of Motrin (ibuprofen) for a 3-year-old patient weighing 14-15 kg with fever and cough?

Ibuprofen (Motrin) Dosing for a 3-Year-Old Child

For a 3-year-old child weighing 14-15 kg with fever and cough, administer ibuprofen 10 mg/kg per dose (140-150 mg), which can be given every 6-8 hours as needed, not exceeding 3-4 doses in 24 hours (maximum 30-40 mg/kg/day). 1

Weight-Based Dosing Algorithm

• The recommended dose is 10 mg/kg per dose for optimal antipyretic and analgesic effect 2, 3
• For a child weighing 14 kg: 140 mg per dose
• For a child weighing 15 kg: 150 mg per dose
• This dose can be repeated every 6-8 hours as needed 1
• Maximum daily dose should not exceed 30-40 mg/kg/day (420-600 mg total for a 14-15 kg child) 1

Dosing Frequency and Timing

• Administer every 6-8 hours as needed, which translates to a maximum of 3-4 doses in 24 hours 1
• Maximum fever reduction occurs 3-4 hours after administration 3
• The duration of antipyretic effect is longer than acetaminophen, supporting less frequent dosing 3

Clinical Effectiveness

• Ibuprofen 10 mg/kg is equally effective as acetaminophen 15 mg/kg for fever reduction and has a longer duration of action 2, 3
• Clinical trials demonstrate that the effective dose range is 7.5-10 mg/kg, with 10 mg/kg providing optimal results 3
• The relationship between dose and response is linear over the 5-10 mg/kg range 3

Safety Considerations for This Age Group

• Ibuprofen is considered safe for short-term use in children older than 3 months with body weight above 5-6 kg when special attention is given to hydration 1
• The adverse effect profile in children is favorable, with ibuprofen being better tolerated by children than adults 3
• Ensure adequate hydration status before and during treatment 1

Combination Therapy Considerations

• If fever persists or is difficult to control, alternating or combining ibuprofen with acetaminophen (15 mg/kg) can provide superior antipyresis 4, 5
• Combined therapy provides an additional 2.5-4.4 hours without fever compared to single-agent therapy 4
• If using both medications, carefully record all dose times to avoid exceeding maximum recommended doses 4
• The risk of inadvertently exceeding maximum doses increases to 8-11% when using combination therapy 4

Common Pitfalls to Avoid

• Do not use lower doses (5 mg/kg or less) as they are less effective after the initial dose 2
• Avoid the rectal route in young children due to erratic absorption 1
• Do not exceed 3-4 doses in 24 hours or the maximum daily dose of 40 mg/kg 1
• Ensure the child is adequately hydrated before administering ibuprofen 1

When to Reassess

• Most children with fever should show improvement within 24-48 hours 4
• If fever persists beyond 48 hours or the child's condition worsens, further evaluation is needed 4
• Approximately 25% of febrile children return to normal by 48 hours 4