ABSTRACT
The drug pharmacokinetic behavior and response observed in different patients after administration of the same dose of the same drug can be variable. There are many factors that can contribute to this variability including genetic factors, diseases, body weight, age, drug interactions, gender, nutritional status, smoking, environmental factors, seasonal variation, and so on. Some of these factors can be quantitatively correlated with the variation in the drug pharmacokinetics and response, such as the eliminating organ dysfunction, while quantitative relationship cannot be established between the pharmacokinetic variability and other factors such as gender, nutritional status, environmental factors, and seasonal variation. Also, the effect of each of these factors on the pharmacokinetics behavior of different drugs is not the same. The effect of the reduction in kidney function on the rate of drug elimination
is more signicant on the renally eliminated drugs, and the effect of obesity on the pharmacokinetic behavior of hydrophilic and lipophilic drugs is different.
