What is the recommended dose of ibuprofen (nonsteroidal anti-inflammatory drug (NSAID)) for a 15-year-old patient with unknown medical history?

Ibuprofen Dosing for a 15-Year-Old

For a 15-year-old patient, use adult dosing: 400 mg every 4-6 hours as needed, with a maximum daily dose of 2400 mg (or 3200 mg under physician supervision for severe conditions). 1, 2

Standard Dosing Regimen

• Adolescents weighing more than 40 kg (which includes most 15-year-olds) should receive adult dosing guidelines. 1
• The standard dose is 400 mg every 4-6 hours as needed for pain or fever relief. 2
• Maximum daily dose is 2400 mg for over-the-counter use without physician supervision. 3, 2
• For prescription use under medical supervision, the FDA allows up to 3200 mg daily, though doses above 2400 mg show minimal additional benefit and significantly increased risk. 3, 2

Duration of Treatment

• Use the lowest effective dose for the shortest duration to minimize gastrointestinal, cardiovascular, and renal toxicity. 3
• For acute pain or fever, limit use to 5-10 days maximum without medical evaluation. 3
• If pain persists beyond 2 weeks, investigate for underlying treatable causes rather than continuing ibuprofen indefinitely. 3

Critical Safety Considerations Before Prescribing

Absolute contraindications that require avoiding ibuprofen entirely: 4, 3

• History of NSAID-associated gastrointestinal bleeding
• Active peptic ulcer disease
• Aspirin-exacerbated respiratory disease (asthma with nasal polyps)
• Severe renal impairment or chronic kidney disease
• Heart failure
• Cirrhosis

Use with extreme caution in patients with: 4, 3

• Hypertension (ibuprofen increases blood pressure by mean of 5 mm Hg)
• History of peptic ulcer disease (5% risk of bleeding recurrence within 6 months even with protective measures)
• Concurrent anticoagulant use (increases GI bleeding risk 3-6 times)
• Concurrent corticosteroid or SSRI use
• Asthma (particularly with history of sinusitis or nasal polyps)

Important Drug Interactions

• If the patient takes low-dose aspirin for any reason, ibuprofen must be taken at least 30 minutes AFTER immediate-release aspirin or at least 8 hours BEFORE aspirin to avoid blocking aspirin's cardioprotective effects. 3
• Never combine with other NSAIDs or multiple acetaminophen-containing products without dose adjustment. 1
• Check for "hidden sources" of NSAIDs in combination cold/flu medications. 3, 1

Administration Guidelines

• Administer with food or milk if gastrointestinal complaints occur. 2
• Ensure adequate hydration, as dehydration increases renal toxicity risk. 5
• For adolescents under 40 kg, calculate dose as 10 mg/kg per dose (maximum 400 mg per dose). 1, 5

When to Stop Immediately

Discontinue ibuprofen and seek medical attention if: 3, 5

• Any signs of gastrointestinal bleeding (black stools, coffee-ground vomit, abdominal pain)
• Development or worsening of hypertension
• Decreased urine output or fluid retention
• Severe rash or allergic reaction
• Worsening asthma symptoms

Common Pitfalls to Avoid

• Do not exceed 2400 mg daily without physician supervision, as cardiovascular and gastrointestinal risks increase substantially at higher doses. 3, 2
• Do not use for more than 10 days for acute conditions without medical re-evaluation. 3
• Do not assume all adolescents can take adult doses—verify weight is above 40 kg first. 1
• Do not combine with aspirin therapy without understanding the timing requirements to preserve aspirin's effects. 3

Alternative Considerations

• If ibuprofen is contraindicated or causes side effects, acetaminophen 500-1000 mg every 6 hours (maximum 3000 mg daily) is a safer alternative with fewer gastrointestinal, renal, and cardiovascular risks, though potentially less effective for inflammatory pain. 3
• For localized musculoskeletal pain, topical NSAIDs minimize systemic exposure and may be preferable. 3