Intravenous linezolid was efficient and well tolerated in critically ill premature infants. PNA was the main determinant of clearance.

Objective: To compare the safety and efficacy of phenobarbital and levetiracetam in a cohort of neonates with seizures following cardiac surgery. Methods: We performed a retrospective single-center study of consecutive neonates with electrographically confirmed seizures managed with antiseizure medication after cardiac surgery from June 15, 2012 to December 31, 2018. We compared the safety and efficacy of phenobarbital and levetiracetam as first-line therapy. Results: First-line therapy was phenobarbital in 31 neonates and levetiracetam in 22 neonates. Phenobarbital was associated with more adverse events (P = .006).Eight neonates (14%) experienced an adverse event related to phenobarbital use, including seven with hypotension and one with respiratory depression. No adverse events were reported with levetiracetam use. The cessation of electrographic seizures was similar in both groups, including 18 neonates (58%) with seizure cessation after phenobarbital and 12 neonates (55%) with seizure cessation after levetiracetam (P = 1.0). The combined cessation rates of phenobarbital and levetiracetam when used as first-or second-line therapy were 58% and 47%, respectively (P = .47). Significance: Phenobarbital was associated with more adverse events than levetiracetam, and the two drugs were equally but incompletely effective in treating electrographically confirmed seizures in neonates following cardiac surgery.Given its more acceptable safety profile and potential noninferiority, levetiracetam may be a reasonable option for first-line therapy for treatment of seizures in this population. Further prospective studies are needed to confirm these results. K E Y W O R D Scardiology, congenital, critical care, heart diseases, infant 628 | THIBAULT eT AL.

Piperacillin-tazobactam (TZP) is frequently used to treat severe hospital-acquired infections in children. We performed a single-center, pharmacokinetic (PK) trial of TZP in children ranging in age from 2 months to 6 years from various clinical subpopulations. Children who were on TZP per the standard of care were prospectively included and assigned to receive a dose of 80 mg/kg of body weight every 6 h infused over 2 h (ages 2 to 5 months) or a dose of 90 mg/kg every 8 h infused over 4 h (ages 6 months to 6 years). Separate population PK models were developed for piperacillin and tazobactam using nonlinear mixed-effects modeling. Optimal dosing was judged based on the ability to maintain free piperacillin concentrations above the piperacillin MIC for enterobacteria and Pseudomonas aeruginosa for ≥50% of the dosing interval. Any untoward event occurring during treatment was collected as an adverse event. A total of 79 children contributed 174 PK samples. The median (range) age and weight were 1.7 years (2 months to 6 years) and 11.4 kg (3.8 to 27.6 kg), respectively. A 2-compartment model with first-order elimination best described the piperacillin and tazobactam data. Both final population PK models included weight and concomitant furosemide administration on clearance and weight on the volume of distribution of the central compartment. The optimal dosing regimens in children with normal renal function, based on the piperacillin component, were 75 mg/kg/dose every 4 h infused over 0.5 h in infants ages 2 to ≤6 months and 130 mg/kg/dose every 8 h infused over 4 h in children ages >6 months to 6 years against bacteria with MICs up to 16 mg/liter. A total of 44 children (49%) had ≥1 adverse event, with 3 of these (site infiltrations) considered definitely associated with the extended infusions.