Which pharmacokinetic reason contributes to increased medication sensitivity in infants?

Increased medication sensitivity in infants can be attributed to a combination of pharmacokinetic factors that alter how drugs are absorbed, distributed, metabolized, and excreted in their bodies. Each of the listed reasons contributes to this heightened sensitivity.

Lower protein-binding capacity is particularly significant because infants have lower levels of serum albumin and other plasma proteins that bind drugs. This leads to a higher proportion of unbound (active) drug in circulation, which can enhance both the pharmacologic effects and potential toxicity of medications.

Decreased medication metabolism is also a crucial consideration. Infants, especially neonates, often have immature liver enzyme systems, which means they metabolize drugs more slowly than older children and adults. This reduced metabolic capacity can lead to prolonged drug action and increased risk of adverse effects.

While renal clearance is typically higher in infants due to their higher total body water and different maturation levels of renal function, this aspect does not necessarily increase sensitivity in the same way that the other factors do. However, it is still an important consideration in the overall pharmacokinetics of infants.

Given these factors, the correct response encompasses the understanding that infants experience increased sensitivity to medications due to a combination of these pharmacokinetic changes, impacting their response to drugs in a