ABSTRACT
The age-associated alterations of the drug dispositions may be described as a general biochemical and physiological expression of aging. Most of the maternal medications cross the placental barrier, which implies that the fetus may be potentially exposed to a variety of pharmacological agents. The rate of diffusion of pharmacologically active molecules across the placenta may be modulated by the physicochemical properties of drug molecules. The incidence of disease increases with age, suggesting that progressive impairment of adaptive response is associated with diseases. The age-dependent changes of the detoxicating enzyme system, the plasma protein concentrations, and the maturity of renal functions are the principal causes which render newborn infants more susceptible than older children to most therapeutic agents. The protein-binding capacity may be complicated by a number of factors including disease states, impaired renal function, nutrition, and multiple drug therapy, which are common to the elderly.
