Acetaminophen Dosing for a 9-Week-Old Infant Weighing 5.51 kg
The recommended acetaminophen dose for a 9-week-old female infant weighing 5.51 kg is 10-15 mg/kg/dose, which equals 55-83 mg per dose, given every 4-6 hours as needed, not to exceed 5 doses in 24 hours.
Weight-Based Dosing Calculation
- Infant's weight: 5.51 kg
- Recommended dosage range: 10-15 mg/kg/dose
- Calculated dose range: 55.1-82.7 mg per dose (rounded to 55-83 mg)
Administration Guidelines
- Oral liquid formulations are appropriate for this age group
- Standard infant formulation concentration is 160 mg/5 mL
- For a 55 mg dose: administer approximately 1.7 mL
- For an 83 mg dose: administer approximately 2.6 mL
- Use a calibrated oral syringe or dropper for accurate measurement
Dosing Schedule
- Administer every 4-6 hours as needed
- Do not exceed 5 doses in 24 hours
- Maximum daily dose: 275-415 mg/day
Important Considerations for Infants Under 3 Months
- Use acetaminophen only when clearly indicated for pain or fever
- Start at the lower end of the dosing range (10 mg/kg) for initial doses
- Carefully monitor the infant for response and any adverse effects
- Potential for overdose is higher in infants under 3 months of age 1
- Ensure accurate weight-based dosing calculation to prevent potential toxicity
Safety Precautions
- Double-check all dose calculations before administration
- Use only infant formulations (not children's or adult formulations)
- Do not combine with other medications containing acetaminophen
- Consult healthcare provider if symptoms persist beyond 24 hours or worsen
- Store medication safely out of reach of children
When to Seek Medical Attention
- If fever persists beyond 24 hours in an infant this young
- If the infant shows signs of worsening illness
- If there are concerns about proper dosing or administration
- For any unusual symptoms or reactions after medication administration
Remember that acetaminophen should be used at the lowest effective dose and for the shortest duration necessary in infants this young. Always consult with a healthcare provider before administering any medication to infants under 3 months of age.