*Unit 2 - Physiologic Concepts of Pharmacology Flashcards
Pathways for Drugs (3)
- Direct penetration
- passage through protein channels
- carrier proteins
Mechanisms (3)
- passive diffusion
- facilitated diffusion
- active transport
the study of the movement of drugs within the body
pharmacokinetics
4 ways of pharmacokinetics
- absorption
- distribution
- metabolism
- excretion
the rate and extent that a drug leaves the site of administration
absorption
which administration route has the fastest absorption rate
Intravenous (IV)
What is the advantage of administering a medication intradermally
- it causes very slow systemic absorption (the blood stream doesn’t pick it up quickly and doesn’t deliver it to the rest of the body quickly so it stays localized) (ex. allergy shots & TB shots)
what would be the advantages of transdermal (on top of the skin) drug delivery systems (ex. rubbing cream, patch, etc.)
- very slow, not readily absorbed
what would be the disadvantages of transdermal (on top of the skin) drug delivery systems (ex. rubbing cream, patch, etc.)
- skin irritation
- may need additional drugs to control symptoms you’re trying to control (ex. pain meds)
what other factors effect drug absorption (6)
- drug concentration and dose
- GI tract environment
- blood flow
- drug ionization
- interactions
- surface area
the rate and extent to which the active ingredient is absorbed from a drug product and becomes available at the site of drug action or produce its effect
bioavailability
mechanism whereby drugs are absorbed, enter into the hepatic portal circulation, and are inactivated by the liver before they read the general circulation
first-pass effect
tablets or capsules designed to dissolve very slowly, resulting in a longer duration of action for the medication; also called long-acting sustained release
extended release
tablets that have a hard, waxy coating designed to dissolve in the alkaline environment of the small intestine
enteric-coated
bioavailability
the rate and extent to which the active ingredient is absorbed from a drug product and becomes available at the site of drug action or produce its effect
first-pass effect
mechanism whereby drugs are absorbed, enter into the hepatic portal circulation, and are inactivated by the liver before they read the general circulation
extended release
tablets or capsules designed to dissolve very slowly, resulting in a longer duration of action for the medication; also called long-acting sustained release
enteric-coated
tablets that have a hard, waxy coating designed to dissolve in the alkaline environment of the small intestine
molecules are going from high to low concentration
passive diffusion
molecules are going from high to low concentration, however, you need a carrier protein in order to help facilitate the diffusion
facilitated diffusion
requiring energy in order for the molecules to get through the cell membrane
active transport
how quickly a drug starts working
onset of action
will a drug act faster if i take a higher dose
Yes
page 30
True/False: food will ALWAYS slow down absorption
TRUE!!!
True/False: oral drugs can affect how fast/slow the GI tract moves
True
What affect on absorption does oral medications have on a patient who doesn’t have a lot of blood flow to the GI tract/small intestine?
???
Why do oral medications get more absorbed in the small intestine rather than in the stomach
???
True/False: most medication are absorbed in the stomach
FALSE! most are absorbed in the small intestine!
what is the major “transportation system” of drugs for distribution to the body tissues
cardiovascular system
True/False: Medications pick and choose where they want to go
FALSE! They travel throughout the whole body through the bloodstream and they react with certain receptors within certain areas of the body
the transport of a drug within body fluids to body tissues
???
Drug distribution can be affected by the following variables:
- blood flow
- drug solubility
- tissue storage
- protein building
- blood-brain, fetal-placental barrier
the changing a drug to be more easily excreted (scientific - technical term - know “metabolism” instead)
biotransformation
True/False: a drug that is active can be metabolized into inactive metabolites
true
True/False: a drug that is active can be metabolized into still active metabolites
true
True/False: a drug that is inactive is changed into an active drug through metabolism
true (prodrug)
a drug that is inactive is changed into an active drug through _____
metabolism
the body attempts to neutralize or ______ substances for excretion changing fat soluble drugs into water soluble metabolites that can be excreted from the kidney
detoxify
The body attempts to detoxify/neutralize substances for excretion changing ______ into _____ that can be excreted from the ________
fat soluble drugs
water soluble metabolites
kidney
???
substrates
increased enzyme production
induction
result of induction
more drug metabolized and need higher doses
inhibiting liver enzymes
inhibition
result of inhibition
less drug metabolized and more drug in blood
after absorption, drugs may be extensively metabolized before reaching the rest of the body
first-pass phenomenon
List the patient specific variables that effect metabolism
- lifespan/age
- lifestyle/habits
- diet
- liver disease
- genetics
(3 paragraphs on page 35 for detailed explanation for variables that cause differences in metabolism in different patients)
elimination of a drug, either unchanged or as a metabolite, from the body
excretion
altered in renal failure
renal secretion
altered in liver failure
hepatic secretion
drug secretion in bile
bile is reabsorbed so metabolites may be recycled multiple times
Your patient has been and alcoholic for 25 years. What affects on pharmacokinetics for you expect?
??? they’re not going to be very efficient/fast ???
amount of drug in the blood
serum drug level
amount of drug in the blood required to get a drug action
minimum effective concentration (MEC)
too much drug causes toxic reactions
Toxic Concentration
between the MEC and the Toxic Concentration levels
Therapeutic Range
Periodic doses to keep blood levels in therapeutic range
Maintenance Dose
a large initial dosing of a drug to achieve rapid minimum effective concentration in the plasma
Loading Dose
Plasma is in the blood: if you were to spin and separate the plasma from blood cells, the drug would be within the water/plasma part. The proteins are in the plasma.
highest and lowest plasma concentration of a drug
Peak and Trough Levels
FYI: Plasma drug concentration graph on page 38 to show therapeutic range
:)
minimum effective concentration
onset
highest blood level
peak
length of pharmacological action
duration
time required for serum concentration to be decreased by 50%
Serum Half-Life
short half-life requires…
more frequent dosing
long half life requires…
less frequent dosing
the dose at which a drug will produce its therapeutic effect (How strong is it)
potency
the greatest response that can come from a drug (Does it do what it’s supposed to do)
efficacy
effect and potency of a drug action is dependent on…
the unique characteristics of the drugs and the receptors
availability of receptor sites influences…
drug action
chemical make-up of drugs affects…
the ability to bind to receptor sites
these are drug binding sites
receptors
the effect of what can stimulate or inhibit cell function
receptors
drug binding to a _____ in the ________ can change the permeability of the cell membrane
receptor
cell membrane
promote or produce a response
agonist
block a response
antagonist
puzzle pieces, locks and keys, little pieces of proteins that sit on the outside of cells and fit together with chemicals or drugs, very specific
receptors
receptor desensitization can occur through repeated or long term stimulation
She talked about receptors
down regulation
excess excitatory responses can be noted if receptor has been repressed for a long time and then a small dose of a stimulating drug is given
She talked about receptors
up regulation
how many different kinds of receptors will lock with a certain drug or will a certain drug affect
specificity/selectivity
- this is usually what causes adverse affects
True/False: primary and secondary effects fall hand in hand with unlabeled uses
True, because though benadryl (Diphenhydramine) is used to help with hayfever symptoms, a sider effect is sleepiness, so it can also be used to help with sleeping
indications for use and also used for other “non-approved” purposes
primary and secondary effects
an effect that occurs other than the desired therapeutic effects of drug therapy, or an effect that is harmful
adverse effects
minor vs. life-threathening
side effects vs. toxicity
a warning that the drug has a risk of serious or potentially fatal effects
black box warning
abnormal exaggerated response to an antigen
hypersensitivity
abnormal reaction to a drug because a prior exposure stimulated the immune system to develop antibodies…antigen-antibody response
drug allergy
Most serious allergic reaction. A medical emergency. Systemic reaction evidenced by dyspnea, cardiac arrhythmias, laryngeal edema, bronchospasm and circulatory collapse
Anaphylaxis
A patient says they’re allergic to lortab because they keep throwing up, is throwing up because of a medication a true allergic response
NO!
an allergic response actually means that the person is having a reaction with the ________
immune system
Follow up question when asking what medication patients are allergic to. Why do we ask them this?
What does that medication do to you?
- because throwing up is not necessarily an allergic response
- because many people get itching from narcotics (ex. morphine), however unless they have hives or skin reaction in addition to itching, it’s not really considered a reaction (it’s more an benign side effect)
Is itching because of morphine an allergy?
Not unless it is an addition to hives or a skin reaction@ If not, it’s a benign side effect.
an unanticipated, unexplainable response to a drug
idiosyncratic drug response
often referred to as a paradoxical response
idiosyncratic drug response
another name for idiosyncratic drug response
paradoxical response
is an idiosyncratic drug response considered an allergic reaction
NO
drug that may cause cancer
carcinogen
drug that may cause birth defects
teratogen
3 types of adverse effects
- idiosyncratic drug response
- carcinogen
- teratogen
3 types of allergic reactions
- hypersensitivity
- drug allergy
- anaphylaxis
nonspecific and nonselective drug effects
specificity/selectivity
the study of the mechanisms of drug action and how the body responds to it
pharmacodynamics
Pregnancy Classifications - Teratogens
A (no harm to babies) B (pretty safe) C D X (HARM TO BABIES)
(page 95)
Types of Adverse Effects:
Neurotoxicity/central nervous system
- depression (sleepy, lethargic)
- stimulation (can’t sleep, anxious, excitable)
- ototoxicity
Gastrointestinal Effects
NVDAC Nausea Vomiting Diarrhea Anorexia Constipation
adverse effect on the bone marrow
hematological effects
- it can effect (reduce or damage) the production of white & red blood cells & platelets (any kind of blood cells)
hematological
adverse effects that damage the kidneys
nephrotoxicity
adverse effects that damage the liver
hepatotoxicity
adverse effects that damage the heart
cardiotoxicity
True/False: Most drugs are metabolized through the kidneys and excreted through the liver
FALSE! most drugs are metabolized through the liver and excreted through the kidneys
adverse effects that damage the neurons/central nervous system
neurotoxicity
True/False: a lot of drugs with have some sort of effect on the GI tract
True
True/False: all of these are types of adverse effects:
- hematological effects
- dermatologic effects
- muscles and tendons
True
when 2 different drugs from the same therapeutic class are used together for a greater response
additive effect
when 2 drugs create a bigger response than what you would think if you simply combined them together (meds from different classes)
synergistic effect
one drug blocks the effects of another drug
antagonistic
displacing one drug from protein binding sites increases the amount of free drug thereby increasing the drug effect (protein binding: in class object lesson)
displacement
True/False: drug and food interactions can cause adverse effects due to changes in pharmacokinetics
True
needing more drug to achieve the desired effect
drug tolerance
- withdrawal
- physical dependence
- psychological dependence (body thinks they need it in order to normally function…brainwashing itself)
- drug seeking behavior
drug dependence
achieving benefit from a compound that does not have the properties to produce the effect
placebo effect
management of a drug overdose
- recognition or identification of drugs taken
- gastric lavage, activated charcoal, and whole bowel irrigation - pluses and minuses
- treat life threatening symptoms (resp arrest, seizures, shock)
- administer antidotes
how do we prevent adverse effects in our patients
(page 53-54)
- obtain thorough med history
- thoroughly assess the patient and all diagnostic data
- prevent med erros
- monitor pharmacotherapy carfully
- know the drugs
- be prepared for the unusual
- question unusual orders
- teach patients about adverse effects
most absorption occurs in the __________, because this portion of the GI tract in longer, and the absorptive surfaces of the microvilli are much more extensive as compared to the stomach
small intestine
potential drug effect on absorption in the presence of food
decreased
potential drug effect on absorption with drug-drug binding
decreased
potential drug effect on distribution if displacement of drug from plasma protein binding site (protein binding: in class object lesson)
increased
potential drug effect on metabolism with stimulation of CYP: enzyme induction
decreased
potential drug effect on metabolism with inhibition of CYP: enzyme inhibition
increased
potential drug effect on excretion if increased excretion
decreased
potential drug effect on excretion if decreased excretion
increased
Therapeutic Index =
median lethal dose (LD)/median effective dose (ED)
True/False: The higher the value of a therapeutic index, the safer the medication
TRUE!
a reflection of a drug’s ability to bind to a receptor
potency
the ability of a drug to produce the desired therapeutic affect
efficacy
What is the pharmacokinetic term for the breakdown of drugs in order to excrete them more easily?
Metabolism
FYI: Need to know in future: highly protein bounded drugs need a lower dosage when administering it to the patient!
:)
Fastest to Slowest drug routes
- IV
- IM
- Oral/intradermal
What type of drugs end in “pril”
ace inhibitors
