What is the recommended dosage of ibuprofen (nonsteroidal anti-inflammatory drug (NSAID)) for children with varying weights and ages, considering their medical history and potential risks such as impaired renal function?

Ibuprofen Dosing for Children

For children aged 3 months and older, ibuprofen should be dosed at 5-10 mg/kg per dose, administered every 6-8 hours, with a maximum of 30-40 mg/kg per day (not exceeding 4 doses in 24 hours). 1

Weight-Based Dosing Strategy

• Standard dose range: 5-10 mg/kg per dose is the established therapeutic range, with clinical trials demonstrating that 7.5-10 mg/kg provides optimal efficacy for fever and pain relief 2
• Dosing frequency: Administer every 6-8 hours as needed, with a maximum of 3-4 doses per 24-hour period 1, 3
• Maximum daily dose: Do not exceed 30-40 mg/kg total per day 1

Age-Specific Considerations

Infants 3-6 Months

• Minimum requirements: Only use in infants older than 3 months with body weight above 5-6 kg 1
• Hydration status is critical: Special attention must be given to ensuring adequate hydration before and during treatment, as dehydration significantly increases the risk of renal damage 1, 4
• Short-term use only: Safety data primarily support short-term use in this age group 1

Children 6 Months to 6 Years

• Standard dosing applies: Use 10 mg/kg per dose for fever and pain 3
• Timing of effect: Maximum temperature reduction occurs 3-4 hours after administration 2
• Duration of action: Ibuprofen provides longer duration of fever control compared to paracetamol (acetaminophen) 2

Critical Contraindications and Precautions

Absolute Contraindications

• Dehydration: Never administer to children with diarrhea and vomiting, with or without fever, due to high risk of renal injury 4
• Neonates: Contraindicated in the neonatal period (under 3 months) 4
• Active varicella (chickenpox): Do not use during varicella infection 4
• Persistent asthma/wheezing: Contraindicated in children with wheezing or persistent asthma 4
• Known NSAID sensitivity: Never give to patients with previous hypersensitivity reactions to ibuprofen or other NSAIDs 4

Renal Impairment

• Avoid in significant renal dysfunction: Ibuprofen should not be used in children with impaired renal function, as it is renally excreted and dehydration compounds nephrotoxicity risk 1, 4

Route of Administration

• Oral route preferred: Oral administration is the standard and most reliable route 1
• Avoid rectal route in young infants: Rectal administration shows erratic absorption, particularly in infants under 6 months, making it unreliable for consistent dosing 1
• Intravenous formulation: IV ibuprofen at 10 mg/kg every 6 hours (maximum 4 doses daily) is safe in infants 1-6 months for hospitalized patients, though this requires medical supervision 5

Important Clinical Pitfalls

Inappropriate Use as Antipyretic

• Fever is not an indication alone: Ibuprofen should not be routinely used as an antipyretic except in rare cases where fever control is medically necessary 4
• Primary indication is inflammatory pain: Ibuprofen remains the drug of first choice for inflammatory pain in children, not simple fever 4

Dosing Errors

• Track all doses carefully: When using ibuprofen, parents frequently exceed the maximum recommended number of doses (11% in one study exceeded limits) 3
• Single agent preferred: If fever control is the goal, use ibuprofen alone first rather than combination therapy with paracetamol, unless the additional 2.5 hours of fever-free time justifies the increased risk of dosing errors 3

Gastrointestinal and Other Adverse Events

• GI events are rare but serious: When gastrointestinal adverse events occur, they can affect both upper and lower digestive tract 4
• Better tolerated than in adults: Clinical experience suggests children tolerate ibuprofen better than adults, and it is safer in overdose than paracetamol or aspirin 2

Practical Dosing Example

For a 10 kg child:

• Single dose: 50-100 mg (5-10 mg/kg)
• Frequency: Every 6-8 hours as needed
• Maximum daily: 300-400 mg (30-40 mg/kg/day)
• Maximum doses per day: 3-4 doses