An Open-label, Pharmacokinetic and Safety Trial Optimizing PreTerm Infant Ampicillin Dosing
The goal of this clinical trial is to learn if preterm infants who are prescribed antibiotics shortly after birth can safety receive a shorter course of antibiotics (24 to 36 hours instead of 48 hours). The main questions it aims to answer are: * Does short-course ampicillin provide high enough levels of ampicillin at 48 hours? * Is short-course ampicillin safe for preterm infants to receive? Preterm infants who are being prescribed ampicillin by their doctor and enroll in the study will stop ampicillin after a shorter than typical course, and researchers will collect blood samples to measure their ampicillin levels and follow them clinically to see how they do after receiving short-course ampicillin. Participants will: * stop ampicillin earlier than 48 hours (between 24 to 36 hours, depending on how premature they are and the dosing of ampicillin their doctor has prescribed) * have one or more blood samples collected, including one around 48 hours from when they started ampicillin * have their data collected until 30 days after they receive short-course ampicillin, or until hospital discharge, whichever is sooner
• Documented informed consent from parent/guardian
• Infants admitted to the Duke Neonatal Intensive Care Unit (NICU)
• less than or equal to 34 completed weeks gestational age (GA) at birth and \< 7 days of life at time of screening
• Prescribed ampicillin by provider per standard of care for evaluation of early onset sepsis