Chapter 2- Principles Of Drug Action And Drug Interactions Flashcards
What is pharmacodynamics?
The study of interactions between drugs and their receptors and the series of events resulting in pharmacological response
Agonists are?
Drugs that interact with a receptor to stimulate a response
Antagonists are?
Drugs that attach to a receptor but do not stimulate a response
Drugs that interact with a receptor to stimulate a response but inhibits other responses are?
Partial antagonists
What is ADME
A: absorption
D: distribution
M: metabolism
E: excretion
What is the study of the mathematical relationships among ADME of individual medicines over time
Pharmacokinetics
What are the most common routes of drug administration?
Enteral, parenteral, and percutaneous routes
How are drugs administered via enteral route?
Directly into the GI tract by oral, rectal, or nasogastric route
How are drugs administered via parental route?
Using subcutaneous, intramuscular or intravenous routes. Aka sub cut, IM, and IV
Inhalation, sublingual, and topical administrations are examples of
Percutaneous routes
The process whereby a drug is transferred from its site of entry into the body to the circulating fluids of the body for distribution around the body.
Absorption
The rate at which absorption occurs depends on?
The route, the blood flow, and the solubility of the drug
Three nursing considerations concerning absorptions are?
1) Administer oral drugs with an adequate amount of fluid usually a large 8 ounce glass of water.
2) Give parenteral forms properly so that they are deposited into the correct tissue for enhanced absorption.
3) Reconstitute and dilute drugs only with the diluent recommended by the manufacturer in the package literature so that the drugs solubility is not impaired
What is an example of an insulin site assessment (nursing implementiations)
If a lump remains at the injection site 2-3 hours later absorption maybe impaired
Rate of absorption when a drug is administered by a parenteral route depends on?
the rate of blood flow through the tissues
What is distribution?
Distribution refers to the ways in which drugs are transported through out the body by circulating body fluids to the site of action, metabolism, and excretion
What are the organs with the most extensive blood supplies?
The heart, liver, kidney, and brain receive the distributed drugs most rapidly.
Muscle, skin, and fat….
Are areas with less extensive blood supplies
Inactive drugs are
Drugs that are bound to plasma proteins
Unbound drugs are able to?
Be active. Defuses into tissues interact with receptors and produce physiologic effect or are metabolized and excreted.
Lipid soluble drugs tend to
Stay in the body longer
Lipid soluble drugs have a?
High affinity for adipose tissue
Distribution may be?
General or selective
What is metabolism?
Biotransformation
Define metabolism
The process whereby the body inactivates drugs
Where is the primary site for metabolism?
The liver
What are important factors for the conversion of drugs?
Genetic variation of enzyme systems, concurrent use of other drugs, exposure to environmental pollutants, concurrent illness and age.
Define excretion
That elimination of drug metabolites and the active drug itself.
What are two primary routes of excretion?
G.I. tract to the feces and renal tubes into the urine
Evaporation through the skin, exhalation from the lungs, and secretion into the saliva and breastmilk are examples of?
Other routes of excretion
A measure of time required for elimination is?
The half-life
Define half-life
The amount of time required for 50% of the drug to be a eliminated from the body
Define onset of action
When the concentration of a drug at the site of action is sufficient to start a physiologic response
What factors affect the onset of action?
Route of administration, rate of absorption, distribution and binding to receptors sites
The time at which a drug reaches the highest concentrations on the target receptor sites are called?
Peak action