What is the recommended dose of paracetamol (acetaminophen) for a pediatric patient?

Paracetamol (Acetaminophen) Pediatric Dosing

The recommended dose of paracetamol for children is 10-15 mg/kg per dose, administered every 4-6 hours, with a maximum of 5 doses per 24 hours (not exceeding 75 mg/kg/day or 4 grams/day total). 1, 2, 3

Standard Dosing by Age and Weight

FDA-Approved Age-Based Dosing (Oral Liquid)

• Children under 2 years: Consult a physician 1
• Children 2 to under 4 years: 5 mL (160 mg) every 4 hours, maximum 5 doses per 24 hours 1
• Children 4 to under 6 years: 7.5 mL (240 mg) every 4 hours, maximum 5 doses per 24 hours 1
• Children 6 to under 12 years: 10.15 mL (325 mg) every 4 hours, maximum 5 doses per 24 hours 1
• Children 12 years and older: 20.3 mL (650 mg) every 4-6 hours, maximum 6 doses per 24 hours 1

Weight-Based Dosing (Preferred for Accuracy)

The weight-based approach of 10-15 mg/kg per dose provides more precise dosing than age-based schedules, particularly for children at the extremes of weight for their age 2, 3. This dosing range has been validated in multiple clinical trials involving over 2,300 children and consistently demonstrates rapid onset of antipyretic effect with maximum temperature reduction occurring approximately 3 hours post-administration 3.

Optimal Dosing Strategy

For maximum efficacy, use a loading dose of 25 mg/kg followed by maintenance doses of 12.5 mg/kg every 6 hours 4, 5. This regimen maintains therapeutic plasma concentrations (4-18 mg/L) more consistently than standard dosing 4.

Rationale for Higher Dosing

• Single doses of 10 mg/kg maintain temperature reduction of 1.5°C below baseline for approximately 6 hours 4
• Doses below 10 mg/kg demonstrate minimal antipyretic effect 4
• The 20 mg/kg single dose shows superior efficacy compared to 10 mg/kg 4
• Clinical and pharmacokinetic data support the 65 mg/kg/day total dose as optimal 5, 3

Administration Considerations

Measurement and Delivery

Use an appropriate measuring device such as a 3-mL or 5-mL oral syringe for infants and young children to ensure accurate dosing 6. Standard household spoons should be avoided due to inconsistent volumes.

Route Considerations

Oral suspension demonstrates greater consistency of response compared to rectal suppositories at equivalent doses (10-15 mg/kg), though both routes show similar overall efficacy 4.

Safety Parameters and Maximum Doses

Daily Limits

• Maximum single dose: 15 mg/kg 2, 3
• Maximum daily dose: 75 mg/kg/day or 4 grams/day (whichever is less) 1, 7
• Minimum dosing interval: 4 hours 1, 2
• Maximum number of doses: 5 doses per 24 hours for children under 12 years; 6 doses for adolescents 12 years and older 1

Toxicity Thresholds

• Acute toxicity: Single ingestions exceeding 150 mg/kg (10 times the recommended dose) are potentially hepatotoxic 7
• Chronic toxicity: Exposures greater than 140 mg/kg/day for several consecutive days carry risk of serious hepatotoxicity and liver failure 7

Special Populations

Hepatic Impairment

Reduce doses and extend dosing intervals in children with hepatic impairment to minimize hepatotoxicity risk 8. The specific dose reduction should be determined based on severity of liver dysfunction, though exact guidelines are not established.

Renal Impairment

Standard dosing can generally be used, but monitor for drug accumulation in severe renal impairment 8.

Clinical Efficacy

Antipyretic Effect

Paracetamol demonstrates equivalent antipyretic efficacy to aspirin at comparable doses (10-15 mg/kg) 4. The onset of temperature reduction is rapid, with measurable effect within 30-60 minutes and peak effect at 2-3 hours 3.

Analgesic Effect

A single 10-15 mg/kg oral dose provides effective analgesia for mild to moderate pain 4, 5. For severe pain, paracetamol offers significant additive analgesic effect when combined with opioids 7.

Common Pitfalls to Avoid

• Underdosing: Many dosing schedules recommend inadequate amounts; ensure doses reach at least 10 mg/kg for therapeutic effect 2, 4
• Incorrect measuring devices: Household spoons provide inconsistent volumes 6
• Exceeding maximum daily dose: Track total daily intake carefully, especially when multiple caregivers are administering doses 7
• Chronic overdosing: Even therapeutic-appearing doses (>140 mg/kg/day) given for multiple consecutive days can cause hepatotoxicity 7

Second-Line Therapy

If paracetamol is ineffective for fever management, ibuprofen may be considered as second-line treatment 6. However, paracetamol remains the first-line choice for both fever and pain in children due to its superior safety profile 7.