ABSTRACT
Metabolism is often required in order for the body to eliminate a drug. Most drugs are given orally and some drugs have variable and incomplete absorption. The major determinant of absorption is the physical properties of the drug. The response of different patients to a drug varies widely and, depending on the drug category, from 20% to 75% of patients do not have a therapeutic response. Many patients will have an adverse reaction to a drug. Some metabolic pathways, such as glucuronidation and amino acid conjugation, are deficient at birth thereby making newborns more sensitive to drugs that are cleared by the enzymes involved. In the case of glucuronidation and newborns, this is particularly important because glucuronidation is the primary mechanism for the elimination of bilirubin, the breakdown product of hemoglobin, and the increase in the levels of bilirubin leads to jaundice.
