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
True or False?
Drugs do not create new responses but alter existing physiologic activity
True
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
How long the drug has a pharmacologic effect is called?
Duration of action
What is a drug concentration time profile?
A time response curve that shows the onset, peak, and duration of action of a drug
What demonstrates the relationship between administration of a drug and response?
Time response curve
What is the desired action?
The expected response
What is another word for side effect?
Adverse effects
What does ADR stand for?
Adverse drug reactions
Define ADR
Any noxious, Unintended, and Undesired effect of a drug used in humans for prophylaxis, diagnosis, or therapy
Right drug, right dose, right patient, bad effect
Adverse drug reaction (ADR)
What does ADE stand for?
Adverse drug events
What is another word for adverse drug events?
Medication errors
Define ADE
Any injury resulting from medical intervention related to a drug
What are commonly seen ADRs?
Rash, nausea, itching, thrombocytopenia, vomiting, hyperglycemia, and diarrhea
Classes of medicine that account for the large number of ADRs are?
Antibiotics, cardiovascular medicine, cancer chemotherapy agents, analgesics, and anti-inflammatory agents
What are two types of drug reactions that are much more unpredictable?
Idiosyncratic reaction and allergic reactions
Define Idiosyncratic reaction
Occurs when something unusual or abnormal happens when a drug is a first administered
True or False?
Idiosyncratic reactions are common
False. They are rare.
Allergic reactions are also known as
Hypersensitivity reaction
Urticaria is another word for?
Hives
What are hives?
Raised, irregularly shaped patches on the skin and severe itching
A severe life threatening reaction causing respiratory distress and cardiovascular collapse is known as
Anaphylactic reaction
True or False?
Anaphylactic reaction is not an emergency
False. It is a medical emergency and must be treated immediately
The ability of a drug to induce living cells to mutate and become cancerous is known as?
Carcinogenicity
A drug that induces birth defects is known as
Teratogen
The greatest potential for birth defects caused by drugs during which trimester?
The first trimester of pregnancy
List the factors that has been identified as a contributor to a variable response to drugs
Age, body weight, metabolic rate, illness, physiologic aspects, tolerance, dependence, and cumulative effect
Which age group is the most sensitive to the effects of drugs?
Infants and the very old
How does bodyweight influence drug action?
Overweight patients require an increase in dosage where as patients who are underweight require lower dosage
How does metabolic rate influence drug action?
People with an higher than average metabolic rate tends to metabolize drugs rapidly needing a larger dose or more frequent administration.
When a person begins to need a higher dosage to produce the same effects that a lower dosage had once provided is known as
Tolerance
Define drug dependence
When a person is unable to control his or her ingestion of drugs
What are two examples of drug dependence?
Physical or psychological
What are two types of drugs that are common for drug dependence
Opiates and benzodiazepines
True or false
A drug may accumulate in the body if the next dose is administered before the previously administered drug has been metabolized or excreted
True
What results in drug toxicity?
Excessive drug accumulation
Inebriated is the same as
Drunk
What occurs when the action of one drug is altered by the action of another drug?
Drug interaction
Two ways drugs interact
1) Agents that, when combined, increase the actions of one or both drugs
2) Agents that, when combined, decrease the effectiveness of one or both of the drugs
Did two examples of drug food interaction
MAOI with wine and cheese, Coumadin with vitamin D
What are food and drug interactions
When food may even increase or decrease or even alter expected response of drug
Define incompatibility
What drugs do not combine chemically with other drugs
Conditions under which the drug should not be given is known as
Contraindications
A drug that counteract the effects of poison or toxicity
Antidote
Antidote for digoxin
Digibind
Antidote for heparin
Protamine sulfate
Antidote for opioid analgesics and heroin
Naloxone, nalmefene
Antidote for benzodiazepines
Flumazenil
Antidote for warfarin
Vitamin K
Poison control phone number?
1-800-222-1222
What measures the amount of a drug present in the blood to determine if it is within the therapeutic range
Drug blood level
Define Synergistic effect
When the combined effect of two drugs is greater than the effect of each drug alone. One plus one equals three.
Define additive effect
When two drugs with similar actions have an increased effect. One plus one equals two
Digoxin is an
Antiarrhythmic
