What is the recommended dose of Motrin (ibuprofen) for a 74-pound adult?

Ibuprofen Dosing for a 74-Pound Adult

For a 74-pound (33.6 kg) adult, the appropriate dose of Motrin (ibuprofen) is 400 mg every 4-6 hours as needed for pain, not exceeding 1200 mg in 24 hours. 1

Dosage Calculation and Rationale

The FDA-approved ibuprofen dosing guidelines indicate that for mild to moderate pain, 400 mg every 4-6 hours as necessary is appropriate 1. This is particularly relevant for this patient because:

• The patient weighs 74 pounds (33.6 kg), which is significantly below the average adult weight
• Clinical studies have shown that doses higher than 400 mg do not provide additional analgesic benefit for acute pain 2
• The lowest effective dose should be used for the shortest duration to minimize adverse effects 1

Maximum Daily Dose Considerations

While the maximum daily dose for average-sized adults is 3200 mg 1, this should be reduced for this lower-weight patient:

• For this 74-pound adult, the maximum daily dose should not exceed 1200 mg (400 mg taken 3 times daily)
• This represents approximately 35.7 mg/kg/day, which stays within safe dosing parameters

Special Considerations for Low-Weight Adults

For this patient with lower body weight:

• The dose is similar to what would be used in children weighing 23-40 kg (50.6-88 lb), who typically receive 60 mg per dose 3
• However, since this is an adult, the standard 400 mg tablet is appropriate as the starting dose 1
• Monitor closely for side effects, as smaller individuals may be more sensitive to medication effects

Administration Recommendations

• Take with food or milk if gastrointestinal complaints occur 1
• Use for the shortest duration necessary to control symptoms
• If pain persists beyond 10 days, medical reevaluation is recommended

Monitoring for Adverse Effects

Be alert for potential side effects, particularly:

• Gastrointestinal effects: nausea, dyspepsia, abdominal pain
• Renal effects: especially if the patient has any underlying kidney issues
• Cardiovascular effects: particularly if the patient has any history of heart disease

Important Precautions

• If the patient is taking aspirin for cardioprotective effects, ibuprofen may interfere with these benefits 4
• Avoid if the patient has a history of GI bleeding, severe renal impairment, or severe heart failure
• For long-term use (which is not recommended without medical supervision), monitoring of blood pressure, renal function, and liver function would be necessary 4

Remember that this dosing recommendation prioritizes safety while providing effective pain relief for this lower-weight adult patient.