A thorough knowledge of the newborn (birth to one month postpartum age) infant’s gastrointestinal tract (GIT) is critical to the evaluation of the absorption, metabolism, distribution, and excretion (ADME) of orally administered drugs in this population. Developmental changes in the GIT during the newborn period are important for nutrient uptake as well as the disposition of orally administered medications. Some aspects of gastrointestinal function do not mature until driven by increased dietary complexity and nutritional demands later in the postnatal period. The functionalities present at birth, and subsequent maturation, can also impact the ADME parameters of orally administered compounds. This review will examine some specific contributors to the ADME processes in human neonates, as well as what is currently understood about the drivers for their maturation. Key species differences will be highlighted, with a focus on laboratory animals used in juvenile toxicity studies. Due to the gaps and inconsistencies in our knowledge, we will also highlight a few areas where additional study is warranted to better inform appropriate use of medicines specifically intended for neonates.
Full text online: http://dmd.aspetjournals.org/content/early/2018/12/19/dmd.118.084418