Paracetamol Dosing for a 7-Month-Old Infant
For a 7-month-old infant, administer paracetamol 15 mg/kg per dose orally every 4-6 hours, with a maximum of 4 doses in 24 hours (not exceeding 60 mg/kg/day). 1, 2
Weight-Based Dosing Algorithm
- Calculate the single dose: Multiply the infant's weight in kilograms by 15 mg to determine the appropriate dose per administration 1, 3
- Dosing interval: Administer every 4-6 hours as needed for fever or pain 1, 3
- Maximum daily limit: Do not exceed 60 mg/kg in a 24-hour period (equivalent to 4 doses at 15 mg/kg each) 2, 3
Example Calculation
For a typical 7-month-old weighing approximately 8 kg:
- Single dose = 8 kg × 15 mg/kg = 120 mg per dose
- Maximum daily dose = 8 kg × 60 mg/kg = 480 mg per day
- This allows for 4 doses of 120 mg each over 24 hours 1
Critical Safety Considerations
Toxicity threshold: Cumulative doses exceeding 90-95 mg/kg/day carry risk of hepatic and renal toxicity, though serious toxicity typically requires exposures greater than 140 mg/kg/day for several days 4, 5
Common prescribing errors: Studies show that 17% of paracetamol prescriptions in children exceed 95 mg/kg/day, though most overdoses are prevented by nursing and pharmacy staff 5
Important Caveats
- Record all doses carefully: Parents should document each administration time to prevent accidental overdosing, particularly if using combination therapy with other antipyretics 3
- Therapeutic range: The 15 mg/kg dose is supported by both clinical efficacy data and pharmacokinetic studies showing this achieves adequate therapeutic concentrations 1, 2
- Alternative dosing in other countries: While the UK uses 10 mg/kg every 4 hours, Australian guidelines recommend 15 mg/kg every 4 hours up to 60 mg/kg/day, which represents the more effective dosing strategy 4
Administration Tips
- Paracetamol can be given as oral suspension, which is the preferred formulation for infants 1
- The medication demonstrates linear pharmacokinetics at therapeutic doses, meaning efficacy is dose-dependent within the recommended range 2
- Onset of antipyretic effect typically occurs within 30-60 minutes of administration 3