Acetaminophen Dosing for an 8-Month-Old Infant
For an 8-month-old infant, give acetaminophen 10-15 mg/kg per dose every 4-6 hours, with a maximum of 60 mg/kg per day or 5 doses in 24 hours. 1
Weight-Based Dosing Approach
- Use 15 mg/kg per dose for optimal effectiveness, as this is the upper end of the recommended range and provides more consistent antipyretic and analgesic effects compared to 10 mg/kg 1
- The 10 mg/kg dose may not reliably achieve therapeutic plasma concentrations needed for fever reduction, whereas 15 mg/kg is more consistently effective 2
- At 8 months old, this infant should weigh approximately 7-10 kg, translating to roughly 105-150 mg per dose 1
Dosing Frequency and Maximum Limits
- Administer every 4-6 hours as needed, not more frequently than every 4 hours 1
- Never exceed 60 mg/kg per day or 5 doses in 24 hours, whichever is lower—this is a critical safety threshold to prevent hepatotoxicity 1
- For example, if giving 15 mg/kg doses every 4-6 hours, you can safely give up to 5 doses in 24 hours without exceeding the daily maximum 1
Formulation Considerations
- Use oral syrup formulation whenever possible rather than rectal suppositories, as oral suspension is absorbed more rapidly and provides more consistent therapeutic response 1
- Rectal acetaminophen has erratic absorption and should be reserved only for situations where the infant is actively vomiting or cannot take oral medication 1
Common Pitfalls to Avoid
- Age-based dosing leads to frequent underdosing or overdosing errors—always calculate the dose based on the infant's actual weight 2
- Many parents inadvertently give inadequate doses (less than 10 mg/kg) or excessive doses (more than 20 mg/kg), so clear weight-based instructions are essential 3
- Do not give doses more frequently than every 4 hours, even if fever persists, as this risks exceeding the maximum daily dose 1