Neonatal Nurse Practitioner Practice Exam

Absorption of an IM injected medication in a neonate is influenced by which of the following factors?

1. Hemodynamic status

2. Membrane permeability

3. Muscle mass

4. Maternal drug history

The correct answer is: Muscle mass

The absorption of an intramuscular (IM) injected medication in a neonate is significantly influenced by muscle mass. In neonates, the muscle development is still immature compared to older children and adults, which can affect how well the medication is absorbed. The smaller muscle mass and less developed vascularity in neonates lead to variations in drug absorption rates; medications may not be absorbed as quickly or effectively as they would be in older patients with more developed muscle tissue. In contrast, hemodynamic status could affect blood flow and, consequently, the absorption of drugs, but it operates more as a secondary factor rather than the primary influence of muscle mass. Membrane permeability plays a role in how drugs cross biological membranes but is less relevant when considering the specific context of intramuscular injection absorption in neonates. Lastly, maternal drug history might inform the presence of certain drugs in the neonate’s system or potential drug interactions but does not directly influence the absorption characteristics associated with muscle mass. Therefore, muscle mass is the primary factor influencing the absorption of IM medications in neonates.