Pharmacodynamics & Pharmacokinetics Notes Flashcards
What is a medication?
a substance used to treat an illness or condition
What is a drug?
any substance that produces a physiologic effect, whether therapeutic or not
Define pharmacology.
the scientific study of how various substances interact with or alter the function of living organisms
The Pure Food and Drug Act of ___ changed (implemented) what?
1906; prohibited the altering or mislabeling of medications
The ___ ___ ___ passed in 1909 prohibited opium importation
Opium Exclusion Act
This act, passed in 1914, restricted the use of various opiates including cocaine
Harrison Narcotics Act
What act gave the FDA enforcement authority for rules requiring that new drugs be safe and pure?
Food, Drug, and Cosmetic Act of 1938
What act implemented a classification system, or schedule, for medications based on the potential for abuse?
Controlled Substance Act (aka Comprehensive Drug Abuse Prevention and Control Act)
The Controlled Substance Act was passed in ___
1970
A Schedule I medication has the (highest/lowest) potential for abuse
highest
Schedule ___ medications cannot be prescribed, dispense, used, or administered for medical use
Schedule I
Schedule II medications have a high potential for abuse but ___ __ __ __ ___
have a legitimate medical purpose/application
Schedule III medications have a (higher/lower) potential for abuse compared to Schedule II medications
lower
A Schedule V medication has a (higher/lower) potential for abuse compare to Schedule II medications
lower
What does the term “off-label” mean?
refers to a situation in which medication is used at different doses or different routes than approved by the FDA
What is a capsule?
powdered or solid medication enclosed in a dissolvable cylindrical gelatin shell
What is a tablet?
Solid medication particles bound into a shape designed to dissolve or be swallowed
What is a powder?
Small particles of medication designed to be dissolved or mixed into a solution or liquid
What is a parenteral solution?
sterile solution for direct injection into a body cavity, tissue, or organ
What is suppository?
medication in a wax-like material that dissolves in the rectum
What are the three different names given to a medication?
Chemical, non-proprietary (generic), and brand name
The ___ ___ ___ classifies medications based on amount of evidence and relative importance
American Heart Association (AHA)
What are the five categories of evidence, as defined by the AHA?
Class(es) I, IIa, IIb, III, and Indeterminate
Class I evidence suggests…
there is strong evidence supporting the use of the medication for the condition
Class IIa evidence suggests…
there is moderate evidence supporting the use of the medication for the condition
Class IIb evidence suggests…
there is weak evidence supporting the use of the medication for the condition
Class III evidence suggests…
the evidence does not support that there is a benefit and may, in fact, support that there is a harmful consequence (treatment may not be helpful and may be harmful)
Class Indeterminate evidence suggests…
research is either just beginning or is in process for a medication, there are no recommendations for or against a medication
The United States Pharmacopoeia - National Formula (USP-NF) recommends that medication be stored between ___ and __ degrees Celsius
15 - 30 degrees Celsius (59 - 86 degrees Fahrenheit)
What is pharmacokinetics?
the action of the body on a medication
What are the body’s four responses to medication administration?
Absorption, distribution, (possibly) biotransformation, and elimination
___ chemcials occur naturally in the body
endogenous
There are ___ sites in proteins connected to cells throughout the body
receptor
Activation of a receptor site can produce one of ___ possible actions
four
One of the possible actions when a receptor sites is activated is that channels permitting the passage of ___ in cell walls are opened or closed
ions
One of the possible actions when a receptor sites is activated is that a ___ ___ becomes activated, initiating other chemical reactions within the cell
biochemical messenger
One of the possible actions when a receptor sites is activated is that a normal cell function is ___
prevented
One of the possible actions when a receptor sites is activated is that a normal or abnormal function of the cell ___
begins
____ chemicals are found outside the body
exogenous
What are agonist medications?
medications that initiate or alter a cellular activity by attaching to receptor sites
___ medications prompt a cell response
Agonist
Agonists can be referred to as (activators/blockers)
activators
What are antagonist medications?
medications that prevent agonist chemicals from reaching cell receptor sites
Antagonists medications can be referred to as (activators/blockers)
blockers
What is affinity?
the ability of a medication to bind with a particular receptor site
What does the term “threshold level” refer to?
the concentration of medication at which initiation or alteration of cellular activity begins
In regards to threshold level, an increase on medication concentration causes a (increase/decrease) in effect until all receptor sites become occupied
increase
What is potency?
the concentration of medication required to initiate a cellular response
As potency increases, the concentration or dose required for cellular response (increases/decreases)
decreases
If potency is low, a (high/low) concentration or dose is required to initiate a cellular response
high
What does the term “efficacy” refer to?
the ability to initiate or alter a cell activity
Once all the cellular receptor sites become bound with agonist medication, what happens to cellular activity?
activity plateaus and no further increase is possible until more receptor sites become available
___ medications can be competitive or non-competitive
antagonist
___ antagonists temporarily bind with receptor sites displacing agonist chemicals
competitive
Noncompetitive antagonists (temporarily/permanently) bind with receptor sites
permanently
The effects of noncompetitive antagonists chemicals will continue until…
new receptor sites or new cells are created
What is a partial agonist chemical
binds to the receptor site but does not initiate as much cellular activity or change as other agonists
Medications are often given based on the patient’s Ideal Body Weight (IBW); what is the formula for calculating a male’s IBW?
kg = 50 + (2.3 x height in inches over 5 feet)
Medications are often given based on the patient’s Ideal Body Weight (IBW); what is the formula for calculating a female’s IBW?
kg = 45.5 + (2.3 x height in inches over 5 feet)
What are the five pregnancy risk categories?
A, B, C, D, and X
The pregnancy risk category A implies that…
the medication fails to demonstrate a risk to the fetus
The pregnancy risk category B implies that…
the medication tested on animals shows no demonstrated fetal risk but has not been tested on humans
The pregnancy risk category C implies that…
results of human and animal studies are not available or animal tests have shown no risk to fetus and there are no controlled human studies
The pregnancy risk category D implies that…
there is positive evidence of human fetal risk but the benefits of use may be acceptable (life-saving medications)
The pregnancy risk category X implies that…
studies in animals and/or humans have demonstrated fetal abnormalities (use clearly outweighs any potential benefits)
What does cumulative action mean?
several smaller doses of a medication produce the same desired clinical effect as a larger single dose
Why would the concept of cumulative action be beneficial for the patient?
allows for the same therapeutic benefit while decreasing the risks associated with administering too much of a medication at once
What is an idiosyncratic medication response?
an adverse effect that is completely unexpected and not previously known to occur
What is LD50?
weight-based dose of a medication that causes death in 50% of animals tested (LD= lethal dose)
What is TD50?
50% of animals tested had toxic effects at or above this weight-based dose (TD = toxic dose)
What is ED50?
Weight-based dose in which 50% of animals tested demonstrated positive effect (ED = effective dose)
The therapeutic index represents the relationship between ___ and LD50/TD50
ED50 (effective dose)
If the therapeutic index is large (the ratio of ED50: LD50/TD50) the medication is considered ___
safe
If the therapeutic index is small (the ratio of ED50: LD50/TD50), the medication is considered ___
unsafe
What is cross-tolerance?
the body can become tolerant of medications within the same class
When repeated doses of a medication are given within a short time, a phenomenon know as ___ can occur
tachyphylaxis
What is tachyphylaxis
rapidly acquired tolerance to repeated doses of a medication in a relatively short amount of time rendering the medication virtually ineffective
What is medication interference?
undesirable medication interactions
AS patients are prescribed a greater number of medications to treat chronic medical conditions, the risk of medication interference (increases/decreases) dramatically.
increases
What does the term bio-availability mean?
percentage of unchanged medication that reaches systemic circulation
Medications administered via IV have ___ % bio-availability
100%
GI medications are subject to __-___ metabolism
first-pass
During first-pass metabolism, medication passes from the GI tract into the ___ ___ and then travels directly to the liver
portal vein
In the liver, medication is ___ potentially inactivating it before it ever reaches systemic circulation
metabolised
Although not preferred, if you absolutely had to administer a medication through an ET tube you should administer __ - __ times the IV dose followed by a 5-10 mL flush
2-2.5
Medications undergoing biotransformation are called ____
metabolites
Metabolites can be either ___ or ___
active / inactive
What are active metabolites?
Metabolites capable of some pharmacological activity
What are inactive metabolites?
metabolites no longer capable of altering a cell process or activity
Most biotransformation occurs in the ___
liver
The two distinct patterns of metabolism and elimination are ___-___ and ___-___ elimination
Zero-order elimination and first-order elimination
During ___ -___ elimination, a fixed amount of a substance is removed during a certain period (regardless of the total amount in the body)
zero-order elimination
During ___-___ elimination, the rate of elimination is directly influenced by the plasma levels of the substance
first-order
During ___-___ elimination, the more substance that is present in the plasma the more the body works to eliminate the substance
first-order
The majority of medications undergo __-__ elimination
first-order
First-order elimination is quantified by __-__
half-life
What is half-life in reference to medications?
time needed in an average person for metabolism of elimination of 50% of the substance in the plasma
The heart has only one receptor for ___ agents
beta (B1)
A beta-1 agonist will (increase/decrease) the body’s heart rate
increase
Alpha agonists will cause ___ in the arteries
vasoconstriction
Beta agonists will cause the arteries to ___
vasodilate
Similar to arteries, the ___ have both alpha and beta receptors
lungs
Alpha agonists cause minor __ in the lungs
bronchoconstriction
Beta agonists cause the lungs to ___
bronchodilate
Sympathomimetric drugs ___ the actions of naturally occurring sympathetic chemicals
mimic
What are the two types of beta sympathetic agents?
beta-1 and beta-2 adrenergic agents
Beta-1 adrenergic agents act primarily on __ beta receptors
cardiac
___ adrenergic agents act primarily on pulmonary beta receptors
beta-2
Sympatholytic drugs ___ the action of sympathetic agents
block
