LESSON 2: Uses, Actions, & Interactions of Drugs in the Body Flashcards
what refers to the long-term reductions in receptor number due to continuous agonist?
downregulation
what refers to what occurs when receptor activation is blocked for prolonged periods by pharmacologic antagonist or by denervation?
upregulation
what deals with a mathematical description of rates of drug movement into, within, and exit from the body, and tells us what dose to give to the patient in order to achieve a concentration that will elicit a response?
pharmacokinetics
pharmacokinetics helps to determine the correct dosage to give to achieve the correct therapeutic concentration so there will be ________ and ________.
less toxicity, excreted properly
the drug should enter _______ as they are the primary means of transport of various materials in the body.
blood vessels
what are the two things that prevent drug accumulation?
metabolism and excretion
as the drug enters the __________, it is distributed to different areas of the body depending on its selectivity before it exert its action at the target site.
systemic circulation.
what deals with relating the dose or concentration to the response?
pharmacodynamics
what deals with the relationship between the dose and the concentration that is achieved by the body?
pharmacokinetics
what is the percentage of the administered dose of a drug that reaches the circulation?
bioavailability
high bioavailability is when?
most of the administered dose goes to the systemic circulation
what are the three things that affect bioavailability?
type of drug, route through which it is given, the metabolic processes it undergoes before reaching the systemic circulation
what type of drugs are 100% bioavailable?
IV drugs
what is the name of the phenomenon when the drug is not yet in the systemic circulation and gets metabolized at a specific location in the body resulting in a reduced concentration of the active drug upon reaching its target site or the systemic circulation?
first pass effect
what are the 4 things that affect the distribution of drugs to its site of action?
its structure, lipophilicity or hydrohilicity, drug properties, affinity towards albumin or its transporter protein
what is the type of drug that is not attached to the binding site and is able to go to the target tissues where it would exert its action?
free drug
this is achieved between the distribution of the drug in the systemic circulation and the tissues up to a point where it reaches its organ of elimination?
equilibrium
metabolism usually occurs where?
liver
excretion usually occurs where?
kidneys
what is the movement of drug from the site of administration to systemic circulation?
absorption
what is the transport of drug in the bloodstream and into organs and tissues?
distribution
what is the biotransformation of drug in the body?
metabolism
what is the elimination of the drug or its compound from the body?
excretion
when you a drug _________, its concentration in the systemic circulation is already ________.
intravenously, high
what is the movement of drugs into the body, through Fick’s Law (Passive Diffusion)?
absorption
the movement of drugs into the body is dependent on what two things?
thickness of the membrane, permeability
what is the passive movement through membranes and other lipid structures?
lipid diffusion
in order for lipid diffusion to occur, the structure needs to be ______ meaning they can cross the membrane because they are lipophilic.
unionized
weak ______ are ionized in an acidic environment meaning they cannot cross membrane
bases
weak _____ are not ionized in an acidic environment meaning they can cross membrane.
acids
transport by special carriers are what?
not governed by Fick’s Law, capacity limited
what is it called when binding to receptors on cell membranes, internalization by infolding of membrane, and contents are released from intracellular vesicle happens?
endocytosis, pinocytosis
______ absorption until it is taken in to the systemic circulation.
slow
upon entering the blood vessels, the specific concentration should ideally fall where?
desired therapeutic range.
why is falling the desired therapeutic range ideal?
this range has been proven to elicit desired response.
at a certain time in the duration of action, the concentration should be ______ the desired therapeutic range.
within
the concentration should not be _______ as to be toxic, but not ______ as to be ineffective.
too high; too low
concentration should be above the _____________________ which is determined by the dose and the elimination of the drug.
minimum effective concentration.
what is the area called when the entire concentration of the drug inside the body that will have an effect and elicit a specific response, and is important in calculating bioavailability?
area under the curve (AUC)
what is it called when 2 drugs that have been marketed at different times need to have the same bioavailability?
bioequivalence
what route has 75 to ≤100% bioavailability, where large volumes are often feasible but may be painful?
intramuscular (IM)
what route has 75 to ≤100% bioavailability, where it is given at smaller volume than intramuscular, and may be painful?
subcutaneous (SC)
what route has 5 to <100% bioavailability, and it is most convenient, and first pass may be significant?
oral (PO)
what route has 30 to <100% bioavailability, and has less first pass compared to oral?
rectal (PR)
what route has 5 to <100% bioavailability, and is often very rapid onset?
inhalation
what route has 80 to ≤100% bioavailability, and is used for lack of first pass effect, and usually very slow absorption?
transdermal
the form of medication will determine what?
its route of administration
the composition of medication is designed to enhance its what?
absorption and metabolism
what refers to the volume of where the drug is distributed in the body, and the ration of the amount of drug in the body to its concentration in the plasma or blood?
volume of distribution
if there is ___ initial concentration or concentration in the blood, the volume of distribution is ____ because the drug travels to different areas.
low; high
what type of drugs usually have a high volume of distribution?
lipophilic drugs
drugs are distributed to areas that have _____, such as the heart, liver, kidneys, and brain?
extensive blood supplies
why are sites like bone and brain difficult for drugs to reach?
due to either poor blood supply or barriers
what are the three areas of slower drug distribution?
muscles, skin, fat
what drugs are the ones that get access to the tissues where they will exert their effects?
free drugs
what drugs will not exert any effect?
protein-bound drugs
what are the 4 determinants of distribution?
size of the organ, blood flow, solubility, binding
what is the biochemical reaction involving a parent drug, and takes place mainly in the liver and produces: an inactive metabolite, a more soluble compound, and a more potent metabolite?
biotransformation
- what phase reaction includes Cytochrome P450 enzymes, and oxidation, deamination, desulfuration, reduction, and hydrolysis?
phase I reaction
what phase reaction includes conjugation, glucuronidation, acetylation, and sulfation, and usually renders drug polar and excretable?
phase II reactions
which labs will the nurse review if there is a concern about the patient’s ability to metabolize drugs?
liver
what are the 3 organs that contribute to the important process of eliminating drugs from the body?
kidneys, liver, bowel
what is the term that refers to the volume of drug that is cleared of the drug, and reveals the function of a kidney?
clearance
what is the rate of elimination that is proportionate to the drug concentration. and where clearance is constant?
first-order elimination
what is the rate of elimination that is proportionate to the drug concentration. and where clearance is constant?
first-order elimination
what is it called when the amount of drug eliminated is constant regardless of concentration?
zero-order elimination
what is the condition in which the rate of the drug elimination is equals the rate of administration, determines dosing intervals, and is reached after 4-5 half-lives?
steady-state concentration
what is the measure of the rate at which drugs are removed from the body?
half-life
most drugs are considered to be effectively removed after about how many half-lives?
five half-lives
a drug should be ______ minimum effective concentration, and ______ toxic dose.
above; below
what is the time it takes for the drug to elicit a therapeutic response?
onset of action
what is the time it takes for the drug to elicit a therapeutic response?
onset of action
what is the time it takes for a drug to reach its maximum therapeutic response?
peak effect
what is the time a drug concentration is sufficient to elicit a therapeutic response?
duration
what is the lowest blood level of a drug?
trough
half-life is constant in ____ order kinetics, while not useful in _____ order kinetics.
first; zero
TRUE OR FALSE. Furosemide, Dobutamine, and Milrinone are drugs for heart failure.
TRUE
antiviral drug with potential to treat SARS-CoV-2 infections; decrease the length of stay in the hospital
Remdesivir
addresses cytokine storm and an IL-6 inhibitor
Tocilizumab
an anticoagulant that addresses the potential thromboembolism in the patient
Enoxaparin
what deals with therapeutic uses and effects of drugs?
pharmacotherapeutics
ordered by the physician and administered by the nurse
drugs in the treatment of disease
concerned with the use of chemicals in the prevention, diagnosis, and treatment of disease especially in humans
Medical Pharmacology
any substance that can affect or lead to a biological response through chemical action
drug
drugs that end on “-mab”
monoclonal antibodies
drugs that are chemically derived
small molecules or small molecule drugs
big drugs with a lot of protein components; produced through a biologic system or a living organism
biologic agents or biologic agent drugs or biologics
frontline in detecting adverse drug events and possible drug interactions
nurses
what are the steps in prescribing a drug?
Step 1: Define the patient’s problem
Step 2: Specify the therapeutic objective/s
Step 3: Verify the sustainability of the P-treatment / Select appropriate P-Drug
Step 4: Start the treatment / Initiate Therapy (Write a Prescription)
Step 5: Give information, instructions, and warnings
Step 6: Monitor and/or stop treatment
what are the goals of therapy?
A. eradicate disease and minimize the impact of disease in the patient’s life
B. relieve symptoms and minimize the potential for adverse effects of the medication
C. prevent disease progression and prevent morbidity and mortality
D. all of the above
D.
what is the aim of minimizing the impact of disease in the patient’s life?
fewer complications
what are the five therapeutic objectives?
- eradication of virus
- relief of symptoms
- decrease morbidity and mortality
- prevent complications
- minimize drug adverse effects
basis of this concern would be pharmacodynamics
efficacy
basis of this concern would be pharmacodynamics and pharmacokinetics
safety
give the seven problems in pharmacotherapeutics
- medication errors
- suboptimal use
- unnecessary therapy
- therapeutic duplication
- unrecognized interactions
- drug allergies
- adverse effects
when do medication errors occur?
during prescribing, transcribing, administration of medication
a reaction between two (or more) drugs
drug-drug interaction
what causes adverse effects of drugs?
individual variation of responses to drugs
what are the two factors that affect response to medication?
(1) drug factors pharmacologic properties and (2) patient factors
TRUE OR FALSE. Drug factors pharmacologic properties corresponds to the following questions:
Right Drug? Right Route? Right Dose?
TRUE
what are the physiologic variables that can affect specific drugs?
age, sex, genetic pattern
what are the pathophysiologic differences that can affect specific drugs?
disease state and severity, comorbidities, concurrent medications
what is the effect of drug on the body?
pharmacodynamics
integration of molecular actions into effect on the body
mechanism of action
dose-response relationship
quantitative terms
can either be receptor-mediated or non-receptor-mediated
chemical action
TRUE OR FALSE. Rarely, the actions of drugs are receptor-mediated.
FALSE. The actions of drugs are MOSTLY receptor-mediated.
pharmacodynamics is largely based on the concept of __________
drug-receptor binding
drug gets to the _______ circulation and to the site of action once administered.
systemic
TRUE OR FALSE. A lot of drugs in the same target of action can increase effectiveness.
FALSE. A lot of drugs in the same target of action can increase toxicity.
receptors largely determine the quantitative relations between ________ of drug and ________
dose or concentration; pharmacologic effects
specific molecules in a biologic system with which drugs interact to produce changes in the function of the system
receptors
where are receptors found?
inside the lipid membrane, within the lipid membrane, or inside the cell
what are receptors responsible for?
selectivity (LOCK AND KEY fashion) of drug actions
receptor and ligand would be selective
LOCK AND KEY fashion
a physiologic response is elicited from the LOCK AND KEY fashion
agonist/activator
inhibit the binding of the ligand which can activate the receptor, and thus, in a way, the receptor is deactivated
antagonist
molecular interactions by which drugs exert their effects
drug-receptor interaction
molecule to which a drug may bind without changing any function, e.g. albumin binding
inert binding molecule or site
binds drugs
albumin
receptors determine the quantitative relations between drug concentration and pharmacologic response
occupational theory of drug action
many drugs are classified on the basis of their ________.
primary receptor affinity
TRUE OR FALSE. Drug receptors are coupled with effectors.
TRUE
molecules that translate the drug-receptor interaction into a change in cellular activity
effectors
what are the four types of receptors?
Ligand-regulated ion channel, G protein-coupled receptors, Receptor Protein Kinases, Intracellular receptor
a type of receptor that contribute to synaptic plasticity; effect in milliseconds
Ligand-regulated ion channel
are metabotropic receptors
G protein-coupled receptors
what is the receptor of drugs that are lipophilic (non-polar) and can cross the membrane easiest?
Intracellular receptor
how long is the lag period of intracellular receptors?
30 minutes to 1 hour
______ can open the area in the DNA-binding domain and cause the transcription of specific genes
binding of the steroid
what will lead to the release of a heat shock protein that’s inhibiting the transcription of DNA-binding domain?
activating or binding to the intracellular receptor
what makes proteins and leads to specific physiologic responses?
translation
the receptor itself is in the membrane and it is an enzyme
receptors on membrane spanning enzymes
bind separate tyrosine kinase molecules; associated with an enzyme inside the cell
receptors located on membrane-spanning molecules
based on chemical or physical properties
non-receptor mediated drug action
what are the four types of non-receptor mediated drug action?
metal chelators, alkalinizing drugs, acidifying drug, osmotic diuretcs
the response to a drug is proportional to the concentration of the receptors that are bound (occupied) by the drug
dose-response relationships
two major types of dose-response relationships
(1) graded and (2) quantal
concentration (log) during graded-dose relationships
X-axis
response during graded-dose relationships
Y-axis
concentration at which the drug elicits 50% of its maximal response
Potency (EC50)
maximal response produced by the drug
Efficacy (Emax)
equal to the concentration of drug that binds 50% of the receptors in the system
Kd
maximal response is possible without 100% receptor occupancy
spare receptors
relating the concentration and the number of the population that responds to a specific or determined response
quantal dose-response graph
the concentration or dose that causes a specified response in
50% of the population under study
ED 50
median toxic dose; dose required to produce a particular toxic
effect in 50% of animals
TD50
median lethal dose; dose required to produce a particular toxic
LD50
Activates receptor with maximal efficacy
full agonist
activates receptor, but not with maximal efficacy
partial agonist
inactivates constitutively active receptor
inverse agonist
decreases agonist potency by binding reversibly to active site of receptor
competitive agonist
decreases agonist efficacy by binding to site other than active site of the receptor
noncompetitive allosteric antagonist
decreases agonist efficacy by binding irreversibly to active site of receptor
noncompetitive active site antagonist
Receptors are dynamically regulated in
location, and sensitivity
loss of response of tissues following repeated or continuous administration of drugs
tachyphylaxis
agonist-bound receptors may be internalized by _____________.
endocytosis
