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. 2026 Mar 13.
doi: 10.1038/s41372-026-02600-5. Online ahead of print.

Evaluating the duration of post-discontinuation therapeutic ampicillin exposures in preterm infants

Angelique E Boutzoukas  1   2 , Jennifer Le  3 , Ryan Kilpatrick  4 , Michael J Smith  5 , Matthew Laughon  6 , Daniel Gonzalez  7   8 , Kelly C Wade  9   10 , Rachel G Greenberg  5   7 , Melissa Babilonia-Rosa  5 , Daniel K Benjamin Jr  5   7 , Michael Cohen-Wolkowiez  5   7 , Kanecia O Zimmerman  5   7
Affiliations

Evaluating the duration of post-discontinuation therapeutic ampicillin exposures in preterm infants

Angelique E Boutzoukas et al. J Perinatol. .

Abstract

Objective: Determine if preterm infants have prolonged therapeutic post-discontinuation antibiotic exposures (PDAE) following empiric ampicillin.

Study design: Prospective study of 27 infants ≤7 days and <37 weeks gestational age (GA) receiving ampicillin (200 mg/kg/day); 49 post-discontinuation PK samples were collected. Exposures were predicted using PK simulations and a prior ampicillin PK model. The probability of target attainment 24- and 36-h after the final ampicillin dose for various minimum inhibitory concentrations (MICs) and the duration of therapeutic PDAE was calculated.

Result: At 24- and 36-h after ampicillin, the probability of exposures ≥1 μg/mL was 95% and 60%, respectively. PDAE (≥1 μg/mL) lasted a median 33 h (95% confidence interval: 15, 79), and varied with GA, from median 53 h (<28 weeks GA) to 27 h (34-36 weeks GA).

Conclusion: Many preterm infants experience therapeutic exposures at least 24 h after the final ampicillin dose. Shorter courses could be considered.

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Conflict of interest statement

Competing interests: The authors declare no competing interests. Ethics approval: The study was approved by Duke University Institutional Review Board (Pro000042519). Participants’ parents or legal guardians completed written consent to participate, and the study was performed in accordance with the Declaration of Helsinki.

References

    1. Stoll BJ, Puopolo KM, Hansen NI, Sánchez PJ, Bell EF, Carlo WA, et al. Early-onset neonatal sepsis 2015 to 2017, the rise of Escherichia coli, and the need for novel prevention strategies. JAMA Pediatr. 2020;174:e200593–e200593. https://doi.org/10.1001/jamapediatrics.2020.0593 . - DOI - PubMed - PMC
    1. Kilpatrick RBA, Benjamin DK, Veeral T, Greenberg RG. Ampicillin exposure initiated in the first three postnatal days in United States Neonatal Intensive Care Units. Poster Presentation presented at: PAS, 25 April 2025, Honolulu, Hawaii. Session Neonatal Infectious Diseases/Immunology 1: Improving antibiotic use in NICU.
    1. Flannery DD, Ross RK, Mukhopadhyay S, Tribble AC, Puopolo KM, Gerber JS. Temporal trends and center variation in early antibiotic use among premature infants. JAMA Netw Open. 2018;1:e180164 https://doi.org/10.1001/jamanetworkopen.2018.0164 . - DOI - PubMed - PMC
    1. Ting JY, Synnes A, Roberts A, Deshpandey A, Dow K, Yoon EW, et al. Association between antibiotic use and neonatal mortality and morbidities in very low-birth-weight infants without culture-proven sepsis or necrotizing enterocolitis. JAMA Pediatr. 2016;170:1181–7. https://doi.org/10.1001/jamapediatrics.2016.2132 . - DOI - PubMed
    1. Cotten CM, Taylor S, Stoll B, Goldberg RN, Hansen NI, Sanchez PJ, et al. Prolonged duration of initial empirical antibiotic treatment is associated with increased rates of necrotizing enterocolitis and death for extremely low birth weight infants. Pediatrics. 2009;123:58–66. https://doi.org/10.1542/peds.2007-3423 . - DOI - PubMed - PMC

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