The area of study which elucidates the time course of drug concentration in the blood and tissues is termed pharmacokinetics a It is the study of the kinetics of absorption, distribution, metabolism and excretion (ADME) of drugs and their corresponding pharmacologic, therapeutic, or toxic response in animals and man a Pharmacokinetics also may be applied in the study of interactions between drugs
◼ The area of study which elucidates the time course of drug concentration in the blood and tissues is termed pharmacokinetics. ◼ It is the study of the kinetics of absorption, distribution, metabolism and excretion (ADME) of drugs and their corresponding pharmacologic, therapeutic, or toxic response in animals and man. ◼ Pharmacokinetics also may be applied in the study of interactions between drugs
I General principles of drug absorption Body membranes are generally classified as three main types those composed of several layers of cells, as the skin those composed of a single laver of cells, as the intestinal epithelium those of less than one cell in thickness, as the membrane of a single cell
I. General principles of drug absorption Body membranes are generally classified as three main types: - those composed of several layers of cells, as the skin, - those composed of a single layer of cells, as the intestinal epithelium, - those of less than one cell in thickness, as the membrane of a single cell
In most instances a drug substance must pass more than one of these membrane types before it reaches its site of action
In most instances a drug substance must pass more than one of these membrane types before it reaches its site of action
Drugs are thought to penetrate these biologic membranes in two general ways: )by passive diffusion 2) through specialized transport mechanisms
Drugs are thought to penetrate these biologic membranes in two general ways: 1) by passive diffusion 2) through specialized transport mechanisms
1) Passive diffusion Passive diffusion is used to describe the passage of (drug) molecules through a membrane which behaves inertly in that it does not actively participate in the process a Drugs absorbed according to this method are said to be passively absorbed
1) Passive diffusion ◼ Passive diffusion is used to describe the passage of (drug) molecules through a membrane which behaves inertly in that it does not actively participate in the process. ◼ Drugs absorbed according to this method are said to be passively absorbed