What is the recommended dose of paracetamol (acetaminophen) for a 9-month-old child weighing 3 kg?

Critical Safety Concern: This Child Requires Urgent Medical Evaluation

This 9-month-old child weighing only 3 kg is severely malnourished (expected weight ~9 kg) and requires immediate medical assessment before any medication administration. The underlying cause of severe failure to thrive must be identified and addressed urgently, as this represents a life-threatening condition that supersedes routine fever or pain management.

Why This Weight is Alarming

• A 9-month-old infant should weigh approximately 8-10 kg based on normal growth curves 1
• A weight of 3 kg corresponds to a newborn or 1-month-old infant 2
• Severe malnutrition at this degree significantly alters drug metabolism, distribution, and clearance, making standard dosing potentially dangerous 1

If Paracetamol Must Be Given (Emergency Situation Only)

Standard Weight-Based Dosing

The recommended dose is 10-15 mg/kg per dose, given every 4-6 hours, not exceeding 60-90 mg/kg/day 1, 2:

• For a 3 kg child: 30-45 mg per dose (using 10-15 mg/kg)
• Maximum daily dose: 180-270 mg/day (60-90 mg/kg/day) 1
• Dosing interval: Every 4-6 hours 3, 2
• Maximum 4-5 doses per 24 hours 3, 4

Critical Dosing Considerations for This Severely Underweight Child

Use the lower end of the dosing range (10 mg/kg = 30 mg per dose) due to:

• Altered hepatic metabolism in malnutrition 1
• Reduced drug clearance capacity 4
• Increased risk of cumulative toxicity at doses >90 mg/kg/day 4

Available Formulation Calculations

For oral liquid paracetamol (160 mg/5 mL concentration, standard in many preparations) 3:

• 30 mg dose = approximately 0.9 mL
• 45 mg dose = approximately 1.4 mL

However, the FDA label states "Children under 2 years of age: Consult a doctor" 3, which is particularly critical given this child's severe malnutrition.

Common Pitfalls to Avoid

• Never use age-based dosing for underweight children - this leads to overdosing in children below the 9th percentile for weight 5
• Do not exceed 90 mg/kg/day cumulative dose - hepatic and renal toxicity can occur with chronic use above this threshold 4
• Avoid the 125 mg suppository mentioned in your question - this would deliver 41.7 mg/kg in a single dose, which exceeds safe single-dose limits for a severely malnourished child 1, 2

Immediate Actions Required

1. Refer to pediatrician or emergency department immediately for evaluation of severe failure to thrive
2. If paracetamol is deemed necessary before medical evaluation, use 30 mg (approximately 1 mL of standard oral suspension) every 6 hours maximum
3. Monitor for signs of toxicity and ensure adequate hydration
4. Document all doses carefully to prevent cumulative overdose 4

The priority is not paracetamol dosing but rather urgent medical evaluation of this child's critical nutritional status and underlying pathology.