PK%2C+PD%2C+PG+key+concepts.docx

Pharmacokinetics: Includes all movement of the drug throughout the body. “What the body does to the drug” Pharmacodynamics: Study of the effects of the drugs and the mechanisms by which those effects are produced. “What the drug does to the body.” Absorption Movement of the drug into the Bloo...

Pharmacokinetics: Includes all movement of the drug throughout the body. “What the body does to the drug” Pharmacodynamics: Study of the effects of the drugs and the mechanisms by which those effects are produced. “What the drug does to the body.” Absorption Movement of the drug into the Bloodstream. Absorption occurs through several methods- passive transport, active transport, pinocytosis. Can be impacted by several factors. *Review and get familiar with the first pass effect & bioavailability. Distribution Distribution of the drug into the Body Tissues. The drug is exiting the vascular system and being deposited to the body tissues. Consider transfer through the capillary beds, placenta, blood brain barrier (BBB), etc. Protein Binding Some drugs have a higher affinity for protein causing them to bind with any circulating protein. If a patient’s protein is high, it gives more binding sites and less circulating free drug. If the protein is low, there will be fewer places for the drug to bind causing increased circulating free drug and effects. Metabolism (Biotransformation) How the body chemically modifies drugs into what can be excreted. *Consider Liver Function- Why? The majority of metabolism occurs in the liver- monitor liver function with AST/ALT. Excretion Removal of the drug from the body. *Consider Kidney Function- Why? The majority of excretion occurs through the kidneys- monitor BUN/Cr levels. Minimum Effective Concentration (MEC) The minimum amount of drug required to produce a drug effect. Half Life The time it takes for the amount of the drug to decrease by 50% in the body. If a drug has a short half-life, that means it leaves the body quickly. If it has a long half-life it leaves the body slowly. Therapeutic Index A way to monitor the concentration of certain drugs is through obtaining a _peak_ and a __trough__ level. They are also known as “titers” or “serum drug levels”. *Some drugs have a narrow therapeutic index and need close monitoring of these levels. Onset, Peak & Duration Onset: Time it takes for the drug to reach minimum effective concentration. Peak: Highest concentration of drug in the bloodstream. Duration: Length of time a drug exerts a therapeutic effect. Receptor Theory (Agonists vs. Antagonists) The proteins tell the cells to activate or inactivate to produce or block a response. Agonist: Turns ON cell response (activates). Antagonist: Turns OFF a cells response (blocks). Non-Specific vs. Non-Selective Non-specific are drugs that affect one receptor, but at multiple sites. Non-selective are drugs that have multiple types of receptors. Pharmacogenetics Grid Pharmacogenetics The study of genetic factors influencing individual response. Focus of Testing Look at specific DNA segments that play a role in the body’s response to a drug. Benefits of Pharmacogenetic Testing 1. Individualized treatment regimen. 2. Decreases drug reactions. 3. Promotes drug adherence. 4. Reduces healthcare costs.