Table 1

Factors affecting toxin absorption and distribution in childrena

ParameterObservationEffect
Gastric pHLess acidic in infantsAltered drug absorption
Gastric emptyingSlower in neonates and infantsDelayed absorption
Intestinal transit timeShorter in childrenReduced absorption
Body surface area relative to weightGreater in childrenIncreased transdermal exposures
Membrane permeabilityGreater in neonatesIncreased cellular uptake
Plasma protein bindingReduced in neonates and infantsIncreased plasma levels of unbound toxin
Body waterTotal body water and extracellular water content higher in neonates and infantsRelatively higher volume of distribution for water soluble toxins
  • a Adapted from Ref. 2 .