Pharmacology Basics Flashcards
Definition:
USP-NF
United States Pharmacopoeia National-Formulary
Defintion:
FDA
Food and Drug Administration
In the FDA approval process, who is the pre-clinical investigation done on?
Animals or Cells
Why is the pre-clinical trails always deemed incunclusive?
It has not been experimented on humans yet
How many phases are in the FDA approval process?
4 phases
When does a trail often die out in the FDA Approval process? And what are the statisitcs?
Phase 2 and Phase 3
In phase 2 there is a 33% success rate and in phase 3 there is a 25%-35% success rate.
Phase 1 of FDA Approval Process
Participants:
Time Frame:
What is it studying?
Success Rate:
20-80 participants
Several Months
Studies Saftey
70% Success Rate
Phase 2 of FDA Approval Process
Participants:
Time Frame:
What is it studying?
Success Rate:
100-300 Participants
Up to Two Years
Studys Efficacy
33% Success Rate
Phase 3 of FDA Approval Process
Participants:
Time Frame:
What is it studying?
Success Rate:
1000 to 3000 Participants
1-4 Years
Studies Safety, Efficacy, and Dosing
25%-35% Success Rate
Phase 4 of FDA Approval Process
Participants:
Time Frame:
What is it studying?
Success Rate:
Thousands of Participants
Over 1 Year
Studies Long term effectiveness, cost effectiveness
70%-90% Success Rate
Why is phase 4 significant?
By phase 4, it is basically approved and being sold
What do pharmaceutical companies do in regards to clinical trails?
-Fund Trails
-Track Effects
-Full Honest Disclosure
-Comply with FDA ruling
-Must Prove the Drug Benefit
-Must Define the Risks
How many phases before a sponsor can submit their treatments to the FDA for consideration to be sold on the market.
must past the third phase
FDA and CDER in regards to clinical trials
-Review Trials
»Look at how they were conducted
-Grant Permission
-Allow Fast Track to Drugs that Show Promise
-Determine Prescription Status
»EX-over the counter, schedule type
-Determine labeling
-Determine Safety Categories
-Remove Unsafe Products (over the counter or prescription)
Definition:
Pharmacokinetics
What the body does to the drug
What are the five routes of administration?
- Oral
- Rectal
- Sublingual
- Transdermal
- Parentarel
Which type of drug administration route is given 80% of the time?
Orally
What are the pros to giving a drug orally?
-cheap
-easy
-can get the drug back if needed
-non-invasive
How fast are oral drugs ingested?
Slower
How are oral drugs ingested?
1) digested and absorbed from stomach/intestines
2) enters the hepatic portal circulation to the liver
3)enters general circulation
Where is the sublingual route?
The drug dissolves underneath the tongue
How is the sublingual administration route of a drug absorbed?
It is absorbed through the mucous membrane into the bloodstream
Where is the transdermal administration route of a drug?
The drug is applied to the skin as a patch and absorbed through the skin
What are the pros and cons of transdermal route of drug adminstration?
Pros: Continuous and long-acting
Cons: May cause irritation
How many type of parenteral injection are there? And what are they and the angles given?
1) IV (into the vein) **25 degree angle
2) IM (into the muscle… ex-vaccine) **90 degree angle
3) SQ (subcutaneous…into the fat…ex-insulin) ***45 degree angle
4) Intrathecal (around the spinal cord) ?
Which is the fastest route of administration of a drug?
Parenteral
Pros and cons of the drug administration route: parenteral
Pros:
- Produces a more rapid response
- avoids unpredictable absorption from the GI tract
- fastest
Cons:
- It is costly
- It can not be retrieved once given
- It is considered more invasive
Which drug administration routes go straight to the systematic circulation?
1) Intravenous
2) Sublingual
3) Rectal
What types of food effect oral absorption?
High Fat Meals—
they take longer to digest and therefor longer absorbtion
What type of emotions effect oral absorption?
Pain and Stress:
It triggers a sympathetic nervous response (fight or flight) which slows down absorbiton
Oral Absorption Route
-Take the Drug
-Goes into the Mouth
-Goes to the Stomach
-Goes to the Intestines
-Goes into portal circulation (nutrient rich blood between the gut and liver where liver can remove harmful substances)
-Goes into systematic circulation (provides functional blood supply to tissues all over the body)
Defintion: Absorption
“Process of moving drug from site of administration into circulation”
In what ways do drugs move throughout the body
-passive
-facilitated
-active trasnport
Drugs move by diffusion, high to low concentration
What can 7 things can effect absorption?
1) Blood Flow
2) pH of environment
3) GI motility
4) Stress
5) Age — the older you are, the slower the absorption
6) Disease State
7) Co-administered drugs or food
Definition:
Bioavailability
The portion of the drug that Is able to produce a pharmacologic response
Ex) Steroids are more bioavailable when taken orally
Ex) Insulin orally will not work and has no bioavailability
Which route of administration has the “first pass effect”
ONLY oral meds
What is the first pass effect
It allows the liver to metabolize or inactivate the drug and harmful substances before it is distributed to the body
True or False:
Drugs can not get metabolized before adequate plasma concentrations are reached
False
How does the first pass effect change the concentrations of the active drug?
It reduces the concentration of the active drug before reaching its site of action or systemic circulation
Definition:
Distribution
The process of moving a drug throughout the bloodstream (circulatory system) to target receptors
What does the amount of distribution to target cells depend on?
Physical and chemical properties of the drug
Ability to penetrate cell membranes, capillary, and blood brain barriers
Where does water soluble drugs go?
Goes into the blood
Where do lipid soluble drugs go?
Goes into the tissues
does water soluble or lipid soluble drugs clear quicker out of the body?
Water soluble clears quicker out of the body
Can water soluble drugs go through pores? membrane?
They are super tiny and can go through pores but get repelled by the membrane
How do water soluble drugs concentrate the blood?
They become ionized (electrical charge) and concentrate in the blood
Where do lipid soluble drugs go to?
Lipophilic drugs will deposit in cellular space and fatty-tissues and have a greater volume of distribution
True or False:
Lipid soluble drugs are non-ionized
True
They do not have an electrical charge
What parts of the body can lipid soluble drugs cross?
They can cross pores, cell membranes, and the blood brain barrier
How would you deal with an infant with little fat when giving a lipid soluble drug?
You would need to give the infant a higher concentration of the drug
Only lipid soluble drugs can pass the blood brain barrier because…
1) It Is not ionized and therefor not reflected at the membrane
2) The blood brain barrier is hydrophobic
The brain has a higher blood flow than the skin so if the drug can break the BBB there is…
a higher concentration of the drug in the brain
What parts of the body have a higher capillary permeability?
The Liver
Has an abundance of capillaries which allows a lot of drugs to flow through
Q: Aspirin and Warfarin are both in the blood stream. Warfarin fits better into the protein than aspirin does. Which of the drug are there more of in the bloodstream now?
Aspirin
What are some types of plasma proteins?
-albumin
-glycoproteins
-lipoproteins
What do drugs bind to in the blood?
Plasma Proteins
How a drug binds to a plasma protein deteremains the extent of the…
1) drug distribution
2) elimination rate
Only unbound or free drugs may…
-diffuse into capillary walls
-produce a pharmacologic effect
-be metabolized
-be excreted
***while bound to a protein, the drug is useless
What is it called when drugs can compete for the same protein and end up increasing “free drug” levels in the blood
displacement
Albumin molecules can become saturated, leaving sufficient free-drugs to interact with…
receptors
Definition:
Metabolism/Biotransformation
Process of oxidizing a drug into inactive products and conjugating them with new molecules to facilitate excretion
Example) CYP enzymes converts lipid-soluble drugs to water-soluble metabolites that can be eliminated by the kidneys
Why do some prescriptions say not to drink certain juices like grapefruit?
Those juices are inhibitors to the CYP 450 enzyme which is needed for metabolism of the drug. Without CYP 450, the drug will become stronger and increases the patients risk for toxicity.
What do CYP450 enzymes do?
They detoxify unusual chemicals, drugs, carcinogens, toxic elements, and pollutants
How does CYP450 oxidize? (Oxidation)
(Phase 1) When an unusual molecule is found, it adds an oxygen atom making the molecule more soluble in water and easily excreted.
— It converts an active compound into an inactive metabolite
What is a “prodrug”?
A biologically inactive compound which can be metabolized in the body to produce a drug and the drugs effects
How does CYP450 create a prodrug?
It converts the main part of the drug (parent compound) to be active by changing the biology of the drug
How does CYP450 conjugate? (conjugation)
The CYP450 enzyme adds a polar molecule to the compound (ionizes it)
This facilitates excretion of the metabolites
***polar molecules (ionized) are more soluble in water and therefore can be excreted easier
Where is elimination and excretion take place?
Mainly Renal
can be repository, skin, bile salts, and feces
True or False:
Good perfusion to the kidneys will bring less conjugated drugs to the glomerulus and into the filtrate.
False:
It will being MORE conjugated drugs to the glomerulus
Does high or low blood pressure means little of the drug will reach the glomerulus?
Low Blood Pressure
When you have a patient with kidney damage, what will you change about their drugs?
You should lower their dosage
Why do protein bound drugs remain in the circulating plasma?
Bigger molecules, like albumin, can not go through the glomerulus
How are ionized drug metabolites excreted or eliminated?
Ionized drugs remain in the circulating plasma and are delivered to the glomerulus and excreted
How are non-ionized drugs excreted or eliminated?
These drugs will move into cellular environments
What is phase one of metabolism/biotransformation?
Oxidation
What is phase two of metabolism or biotransformation?
Conjugation
Where does lipid soluble drugs like to stick?
Subcutaneous fat and cellular space
Can lipid soluble or water soluble metabolites be secreted in breast milk?
lipid-soluble
Geriatric considerations regarding absorbtion
Decreased cardiac output decreases blood flow to the GI tract, which decreases drug absorption
Geriatric considerations regarding distribution
Decreased albumin production allows for high levels of “free drug” which increases the drug effects
Geriatric considerations regrading metabolism
Reduced hepatic enzyme activity and reduced hepatic blood flow reduces the ability to metabolize the drug, which leads to increased duration of the drugs effects
Geriatric considerations regrading excretion
decreased renal function slows renal excretion of metabolites
How are drugs calculated in pediatrics?
Weight must be used for calculating precise drug doses
Do children have an increased or decreased gastric pH?
decreased gastric pH
What is different about infants and young children liver/renal?
there is immaturity involved
Why do absorption rates of medication vary in children and infants?
erratic (unpredictable) blood flow
infants have a higher rate of total body water and lower rates of fat which effects…
lipophilic AND hydrophilic drugs
When half-life is estimated at 4 hours, the concentration of the medications follow what patterns?
Upon taking the medication = 100% medication in the system
After 4 hours of the medication = 50% is left in the system
After 8 hours of the medication. = 25% is left in the system
After 12 hours of the medication = 12.5% is left in the system
after 16 hours of the medication = 6.25% is left in the system
Definiton:
Half-Life
The amount of time for the plasma concentration of the drug to be reduced by half
With repetitive doses, steady state could be achieved after how many half lives?
3-5 half-lives
How many half-lives does it take for a single dose of the medication to be excreted?
4-5 Half-Lives
Defintion:
Steady State
Drug in = drug out
What can prolong half-lives?
organ disease or drug interactions
Defintion:
Loading Dose
One big dose of the drug to get quickly to a steady state
Defintion:
Maintenance Dosing
The process of slowly administrating a drug to get to a steady state
What is the minimum effective drug concentration?
The amount of drug required for therapeutic effect
»>good response to the drug
What is a toxic concentration of a drug?
The level of drug that results in serious adverse effects
What is the duration of action?
The amount of time the drug maintains it’s therapeutic effect
What is the therapeutic range?
The concentration between minimum effective dose and toxic concentration
»>some drugs have a small therapeutic range
Definition:
Pharmacodynamics
Biological response with a drug and the target cells
What do drugs change in body cells
Drugs change the environment of body cells
EX) antacids can neutralize stomach acidity
Where do drugs bind to receptors which creates a signal transduction and will alter cells physiology?
cell membrane
Defintion:
Agonist
Drug that binds to a certain (specific) receptor and stimulates it to produce a physiologic effect
Definition:
Antagonist
Drug that binds to a specific receptor and blocks other substances from stimulating it.
(Binds but doesn’t activate it)
What do selective drugs have fewer of?
Fewer side effects
They can be less selective when higher doses are administered though
What makes a selective drug picky?
They are picky to what receptors they will bind to and wants only certain receptors
A drug that is selective will…
Have only one effect when binding to a receptor
Nonselctive drugs will bind to many different receptors, these receptors can be….
the receptor the drug is SUPPOSED to bind to and then also the other receptors which produce adverse/side effects
What is allohsteric binding?
-When a drug does not bind to the receptor
-It binds “allosterically” (next-door)
-This changes the receptors shape which changes what can bind
Defintion:
Drug Effectiveness
The relationship between the dose of the drug and the magnitude of the effects
Effectiveness = relative to therapeutic index
ex) A few Advil will work but 50 Advil won’t make a difference physically
What two reasons will a drug very on effectiveness?
1) different sites of action
2) different affinities for receptors
Defintion:
Efficacy
magnitude of max response produced by a drug
Definition:
Potency
How to compare drugs:
EX) If a drug is more potent it will produce a therapeutic effect at a lower dose
Definition:
Idiosyncratic Effect
When a drug has the opposite effect than expected
EX) Benadryl will make some kids more awake than sleepy
What is a controlled substance?
When a drug is at significant risk of being abused it is placed into five categories.
Schedule 1 Drugs
Illegal Substances
EX) Marijuna, Heroin
Schedule 2 Drugs
High potential for abuse; severe physical/psych dependence
EX) Opioids and Stimulants
Schedule 3 Drugs
moderate/low potential for abuse/dependence
EX) Anabolic Steroids, Ketamine, Codeine
Schedule 4 Drugs
Low potential for abuse/dependence
EX) Benzodiazepines, muscle relaxants, tramadol
Schedule 5 Drugs
Lower potential for abuse/dependence
EX) Cough suppressants, Lyrica
Pregnancy Category A
Well studied and tested in humans (vitamins)
Pregnancy Category B
Studied in animals (safe) but not humans
EX) Tylenol
Pregnancy Category C
No human studies, some evidence of injury in animals
***alot of drugs are in this range
Pregnancy Category D
Significant evidence of injury in animals
Pregnancy Category X
Clear association with teratogenic effects (halt the pregnancy or produce a birth defect)
what is the pharmacologic class?
Drugs that share similar mechanisms of action
***These drugs may be more selective than others but they have the same mechanisms of action
Defintion:
Chemical Name
Describes drug molecular structure
Defintion:
Therapeutic Effect
The drug response one hopes to achieve
What did all drugs start as?
Plants, natural sources, animals, or minerals
How do drugs evolve?
Through generations of developing synthetic drugs with similar actions by slightly changing the molecular structure of the drug
Defintion:
Pharmacodynamic effect
The effects of the interactions of the drug with the body
Defintion:
Side Effects
Nonfavorable effects from a drug
**nontherupeutic reaction
**after a while a person should develop a tolerance
Defintion:
Adverse Effects
More serious or life-treating issues…
EX) hopsitilation, or death
What is the generic name of a drug?
Abbreviation of the chemical name
What is the Trade Name of a drug
The brand name developed by the drug company selling the product
***protected by copy write
EX) Benadryl is a trade name and diphenhydramine is the generic name
Legal authority for medication administration comes from
Your states nurse practice act but polices may be directed by professional organizations or insitutions
Medication administration policy
to give meds comes from professional origination standards, hospital policy, or saftey organizations
-FDA
-ISMP (Institute for safe medicine practice)
-MEDMARX (US Pharmacopeia’s anonymous reporting system)
Safety concerns regarding medications include
1) looking alike
2) sounding alike
EX) xanax and zantac
What are the 6 rights?
1) right patient
2) right medication
3) right dose
4) right time
5) right route
6) right documentation
How to avoid medication errors?
-review the 6 rights
-know when to do your med checks
-clarify orders that are unclear
-research unfamiliar drugs
-refuse verbal orders (ask for written orders)
-minimize interruptions
-dont rush
How should you abbreviate unit?
Write “unit”
how are micrograms abbreviated
write
mcg or microgram
How should international unit be abbreviated
no abbreviations
should you write daily? or OD?
write out daily or every other day
Do you use trailing zeros or leading zeros?
Do not use trailing zeros (2.0)
USE leading zero when a dose is LESS THAN a whole unit (0.5)
***important for kids with small doses
What is tall man lettering?
It is used for similar named drugs
EX) HyrOXYzine and HydraALAzine
