Paracetamol Dosing for a 20 kg Child
For a 20 kg child, give 200–300 mg of oral paracetamol (10–15 mg/kg) every 4–6 hours, not exceeding 1200 mg per day (60 mg/kg/day) or 5 doses in 24 hours. 1
Standard Dosing Parameters
- Per-dose range: 10–15 mg/kg, which translates to 200–300 mg for a 20 kg child 1, 2
- Dosing interval: Every 4–6 hours as needed 1, 2
- Maximum daily dose: 60 mg/kg/day = 1200 mg/day for a 20 kg child 1
- Maximum number of doses: Do not exceed 5 doses in 24 hours 1
The American Academy of Pediatrics endorses the 10–15 mg/kg per dose range with the 60 mg/kg/day ceiling, which has been the standard for decades and balances efficacy with safety 1. Oral syrup is absorbed more rapidly and provides more consistent fever reduction than rectal suppositories 1.
Practical Dosing Strategy
- Start with 15 mg/kg (300 mg) for a 20 kg child if fever or pain is moderate to severe, as higher single doses (15–20 mg/kg) are more effective than 10 mg/kg at maintaining temperature reduction for 6 hours 3
- Use 10 mg/kg (200 mg) for mild symptoms or in children with risk factors for hepatotoxicity (see below) 1
- Repeat every 4–6 hours based on symptom persistence, but track each dose carefully to avoid exceeding 5 doses per day 1, 4
High-Risk Situations Requiring Dose Reduction
Reduce the dose to 10 mg/kg (200 mg) per dose in the following scenarios to minimize hepatotoxicity risk:
- Malnutrition or fasting >8 hours without adequate caloric intake 1
- Concurrent use of cytochrome P450 inducers (e.g., isoniazid, phenytoin, carbamazepine), which increase production of the toxic NAPQI metabolite 1
- Pre-existing liver disease, although paracetamol remains safer than NSAIDs in this population 1
Common Pitfalls to Avoid
- Inadvertent overdosing: Parents often give both prescription and over-the-counter products containing paracetamol simultaneously. Emphasize checking all medication labels and recording every dose time 4
- Exceeding maximum daily dose: The 60 mg/kg/day limit is absolute; chronic exposures >140 mg/kg/day for several days carry serious hepatotoxicity risk 5
- Relying on rectal formulations: Suppositories have erratic absorption and may lead to underdosing or accumulation with repeated use; oral syrup is strongly preferred unless the child is vomiting or NPO 1
Efficacy Expectations
- Fever reduction: A 15 mg/kg dose typically lowers temperature by 1.5°C for approximately 6 hours 3
- Onset of action: Oral syrup begins working within 30–60 minutes 1
- Pain relief: A 10–15 mg/kg dose provides effective analgesia for mild to moderate pain 5, 6
When to Consider Ibuprofen or Combination Therapy
- Ibuprofen (10 mg/kg every 6–8 hours) may be used as an alternative in children ≥6 months, but is generally not recommended under 6 months 1
- Alternating paracetamol and ibuprofen (staggered every 3–4 hours) provides an additional 2.5–4.4 hours without fever over 24 hours compared to either agent alone, but increases the risk of dosing errors 1, 4
- If using both medications, meticulously record every dose time to prevent exceeding the maximum recommended doses of either drug 4