Antipyretic Efficacy of Acetaminophen and Ibuprofen in Critically Ill Pediatric Patients

Pediatr Crit Care Med. 2019 Aug;20(8):e386-e393. doi: 10.1097/PCC.0000000000002072.


Objectives: To determine the antipyretic efficacy of acetaminophen (IV, enteral, rectal) and ibuprofen (enteral) in critically ill febrile pediatric patients.

Design: Retrospective cohort study.

Setting: Quaternary care pediatric hospital ICUs.

Patients: Pediatric patients less than 19 years old who were febrile (≥ 38.0°C), received a dose of IV acetaminophen, enteral acetaminophen, rectal acetaminophen, or enteral ibuprofen and had at least one temperature measurement in the following 6 hours.

Interventions: None.

Measurements and main results: A total of 3,341 patients (55.8% male, median age 2.5 yr [interquartile range, 0.63-9.2 yr]) met study criteria. Baseline temperature was median 38.6°C (interquartile range, 38.3-38.9°C) measured via axillary (76.9%) route. Patients became afebrile (87.5%) at median 1.4 hours (interquartile range, 0.77-2.3 hr) after the first dose of medication, a -2.9 ± 1.6% change in temperature. Antipyretic medications included as follows: enteral acetaminophen (n = 1,664), IV acetaminophen (n = 682), rectal acetaminophen (n = 637), and enteral ibuprofen (n = 358). Enteral ibuprofen had a significantly greater odds of defervescence on multivariable logistic regression analysis (p = 0.04) with a decrease of -1.97 ± 0.89°C while IV acetaminophen was significant for a decreased time to defervescence at median 1.5 hours (interquartile range 0.8-2.3 hr) after a dose (p = 0.03). Patient age, presence of obesity, and baseline temperature were significant for decreased antipyretic efficacy (p < 0.05).

Conclusions: Enteral ibuprofen was the most efficacious antipyretic and IV acetaminophen had the shortest time to defervescence.

Publication types

  • Comparative Study

MeSH terms

  • Acetaminophen / administration & dosage
  • Acetaminophen / pharmacology*
  • Antipyretics / administration & dosage*
  • Body Temperature / drug effects*
  • Child
  • Child, Preschool
  • Critical Illness / therapy
  • Female
  • Fever / drug therapy
  • Humans
  • Ibuprofen / administration & dosage
  • Ibuprofen / pharmacology*
  • Infant
  • Male
  • Proportional Hazards Models
  • Retrospective Studies


  • Antipyretics
  • Acetaminophen
  • Ibuprofen