Medication Properties
•Pharmacokinetics
•Pharmacodynamics
Pharmacokinetics
Pharmacokinetics - Defined as the study of the way the body processes a drug
A. Includes how drugs are absorbed, reach their site of action, are metabolized and are eliminated from the body.
B. Affects the response of persons to drugs
1. Varies according to age, physical condition, sex, weight time of day, emotional state, other drugs in the body, genetic variations, disease state of the body or immune status
Pharmacokinetics Process
A. Absorption
B. Distribution
C. Metabolism
D. Excretion
A. Absorption
1. How it gets into the circulatory system
2. Bioavailability is the amount of drug that reaches systemic circulation
3. Drugs must be absorbed in order to begin activity
B. Distribution
1. Absorption of drug into the body and its travel to the intended site of activity via circulatory system
2. Affected by several factors
C. Drug Metabolism (Biotransformation)
1. The metabolism of the drug by altering its chemical structure
2. Most drugs metabolized by liver in the hepatic microsomal enzyme system
3. Biotransformation occurs through four major pathways
4. Metabolism affected by many factors
D. Excretion
1. Removal of drug from the body
2. Principally performed by the kidneys
3. Also occurs by way of:
A. Biliary tract
B. Lungs
C. Sweat
D. Saliva
E. Breast milk