Acetaminophen Dosing for an 8-Month-Old Infant Weighing 22 Pounds
For an 8-month-old infant weighing 22 pounds (10 kg), give 150 mg of acetaminophen (Tylenol) every 4-6 hours as needed, not exceeding 4 doses in 24 hours. 1
Weight-Based Dosing Calculation
- The standard pediatric dose is 15 mg/kg per dose for infants, which is the preferred dosing strategy over age-based recommendations 1, 2
- For a 22-pound (10 kg) infant: 15 mg/kg × 10 kg = 150 mg per dose 1
- This dose can be repeated every 4-6 hours as needed 1, 2
Maximum Daily Limits
- Never exceed 60 mg/kg per day (600 mg total for this 10 kg infant) 1
- Maximum of 4-5 doses in 24 hours, regardless of weight 1, 2
- Exceeding these limits risks hepatotoxicity, particularly with chronic overdosing above 140 mg/kg/day for several days 2
Practical Administration
- Use the oral suspension (typically 160 mg/5 mL concentration) rather than suppositories, as the syrup formulation is absorbed more rapidly and provides more consistent response 1
- For 150 mg dose using 160 mg/5 mL suspension: give approximately 4.7 mL (round to nearest measurable increment on dosing syringe)
- Acetaminophen is the only recommended analgesic for infants under 6 months, and remains first-line for this 8-month-old 1
Important Safety Considerations
- The 10 mg/kg dose (which would be 100 mg for this infant) may not achieve adequate plasma concentrations for antipyresis, supporting the use of the higher 15 mg/kg dose 3
- Ibuprofen is generally not recommended for infants under 6 months and should be used cautiously in this age group 1
- If fever persists despite appropriate acetaminophen dosing, medical evaluation is warranted rather than simply adding or switching medications 4