What ibuprofen dose is recommended for a 33 kg child with a juvenile idiopathic arthritis flare according to the BNFC?

Ibuprofen Dosing for JIA Flare in a 33 kg Child

For a 33 kg child with a JIA flare, administer ibuprofen 330 mg (10 mg/kg) per dose, given every 6-8 hours, with a maximum of 4 doses in 24 hours (total daily dose: 1320 mg or 40 mg/kg/day).

Dosing Calculation and Administration

• The standard ibuprofen dose for JIA is 30-40 mg/kg/day divided into 3-4 doses, with individual doses of 7.5-10 mg/kg 1, 2
• For this 33 kg child: 10 mg/kg × 33 kg = 330 mg per dose 2
• Maximum daily dose should not exceed 40 mg/kg/day (1320 mg for this child) 2
• Dosing interval: Every 6-8 hours (maximum 4 doses per 24 hours) 3, 2

Critical Role as Adjunct Therapy Only

• NSAIDs like ibuprofen are conditionally recommended as adjunct therapy for symptom management in JIA, but must NOT delay initiation of disease-modifying therapy 4, 5
• Methotrexate should be started promptly as it induces remission in 60-70% of children with JIA 5
• NSAIDs are not appropriate as monotherapy for chronic, persistent synovitis 4
• An adequate trial of NSAID therapy is 8 weeks while initiating methotrexate 5

Practical Administration Guidance

• Peak temperature reduction occurs 3-4 hours after administration 1
• Oral route is preferred over rectal due to more reliable absorption, especially in younger children 2
• Ensure adequate hydration when administering ibuprofen 2
• Carefully record all dose times to avoid accidentally exceeding the maximum recommended dose 3

Common Pitfalls to Avoid

• Never combine ibuprofen with other NSAIDs, as this increases adverse effects without additional benefit 6
• Do not use aspirin in children with JIA despite FDA approval, due to controversial efficacy, safety concerns, and Reye's syndrome risk 5
• Do not delay methotrexate initiation while using NSAIDs for symptom control 5
• Monitor for gastrointestinal complications, the most frequent adverse effects, particularly with prolonged use 6
• Risk factors requiring gastroprotection include: history of peptic ulcer disease, GI bleeding, concurrent anticoagulant/antiplatelet use, or prolonged high-dose therapy 6

Treatment Escalation Context

• If the JIA flare represents moderate/high disease activity despite current therapy, escalation beyond NSAIDs is strongly indicated 4
• Consider intraarticular glucocorticoid injections for rapidly controlling disease activity, particularly when arthritis prevents ambulation or interferes with important daily activities 4
• Triamcinolone hexacetonide is strongly preferred over triamcinolone acetonide for intraarticular injections 4