Acetaminophen Dosing for a 7-Month-Old Infant
For a 7-month-old infant, give acetaminophen 10-15 mg/kg per dose every 4-6 hours, using the oral liquid formulation, with a maximum of 60 mg/kg per day or 5 doses in 24 hours. 1
Weight-Based Dosing Algorithm
- Calculate the dose based on the infant's weight: Use 10-15 mg/kg per dose, with 15 mg/kg being more effective for adequate fever reduction and pain control 1, 2
- Administer every 4-6 hours as needed: Do not exceed 5 doses in a 24-hour period 1
- Never exceed the maximum daily dose: The absolute maximum is 60 mg/kg per day 1
Preferred Formulation
- Use oral liquid (syrup) formulation: This is absorbed more rapidly and provides more consistent response compared to rectal suppositories 1
- Rectal administration should be avoided when possible due to erratic absorption that can lead to either inadequate analgesia or risk of accumulation 1
Practical Dosing Example
For a typical 7-month-old weighing approximately 8 kg:
- Dose range: 80-120 mg per dose (using 10-15 mg/kg calculation)
- Frequency: Every 4-6 hours as needed
- Maximum daily dose: 480 mg (60 mg/kg × 8 kg)
Critical Safety Considerations
- Weight-based dosing is essential: Parents who dose based on weight are significantly less likely to give inaccurate doses compared to age-based dosing 3
- Infants under 1 year are at highest risk for dosing errors: Studies show 62% of parents give inaccurate acetaminophen doses, with infants being particularly vulnerable 3
- The 10 mg/kg dose may be subtherapeutic: Pharmacokinetic modeling demonstrates that 10 mg/kg often fails to reach therapeutic plasma concentrations (10-20 μg/mL), while 15 mg/kg is more reliably effective 4
Common Pitfalls to Avoid
- Do not use age-based dosing alone: This leads to frequent underdosing or overdosing, particularly in infants 3
- Avoid manufacturer's fixed-dose recommendations without weight verification: These can be inappropriate for individual children 4
- Do not give more frequently than every 4 hours: This increases toxicity risk 1