A Multi-Center Evaluation of the Pharmacokinetics and Safety of Intravenous Ibuprofen in Infants 1-6 Months of Age.

Background: Enteral ibuprofen was first approved as a prescription drug in 1974 for the US market. An intravenous (IV) ibuprofen formulation is approved for use in children older than 6 months of age, but there are limited studies specifically evaluating the pharmacokinetics and safety in children 1-6 months of age.

Aims: The primary purpose of this study was to evaluate the pharmacokinetics of IV ibuprofen in infants younger than 6 months of age. The secondary objective was to evaluate the safety of single and repeated doses of IV ibuprofen in infants younger than 6 months of age.

Methods: This was an industry-sponsored multi-center study. Institutional Review Board approval and informed parental consent were obtained prior to enrollment. Hospitalized neonates and infants younger than 6 months of age with fever or expected postoperative pain were eligible. Enrolled patients received 10 mg/kg of IV ibuprofen every 6 h, with up to four doses per day. Patients were randomized to two sparse sampling technique pharmacokinetic sample time groups. Group 1 samples were drawn at 0, 30 min, and 2 h, while group 2 samples were drawn at 0 min, 1, and 4 h after administration.

Results: A total of 24 children were enrolled in the study, with 15 male patients and 9 female patients. The median age of the cohort was 4.4 months (range 1.1-5.9 months), and the median weight was 5.9 kg (range 2.3-8.8 kg). The arithmetic mean and standard error for peak plasma ibuprofen concentration was 56.28 ± 2.77 µg/mL. Plasma levels declined rapidly with a mean elimination half-life of 1.30 h. Time to peak ibuprofen effect and concentration were similar when compared with older pediatric patients. Clearance and volume of distribution were also similar to those reported in older pediatric patients. No drug-related adverse events were reported.

Conclusions: The pharmacokinetic and short-term safety profiles of IV ibuprofen in pediatric patients 1-6 months of age are comparable to those in children older than 6 months of age.

Trial Registration: Clinicaltrials.gov Trial Registration number and date: NCT02583399-Registered July 2017.