What are the 3 drug phases via PO route
Pharmaceutic
Pharmacokinetic
Pharmacodynamic
Is there a pharmaCEUTIC phase for drugs by other routes other PO
No
Name the 3 parts of the pharmaceutic phase
disintegration
dissolution
rate limiting
What % of drugs are given by mouth
80%
Are PO drugs 100% drugs?
No, all include fillers
What do additives do to a drug
Increase and Decrease absorbabilty of a drug
What is disintegration
Breaking down into smaller particles (Jello chunkiness at bottom of bowl :)
What is dissolution
A process when a drug is dissolved into a liquid to be used by the body (Jello-O at liquid phase)
Rate limiting
Time it takes to go from mouth to absoprtion and dissolution so that the body can use it
What form of drug works rapidly in the GI tract
Liquid
At what pH do drugs dissintegrate and absorb fastest
Faster in acidic (Ph from 1-2)
What do enteric coated drugs do, and when does the function happen?
Resists dissintegration in gastric acid, disintegration happens in alkaline environment of small intestine.
What not to do to the enteric coated drug?
Don't crush, can cause toxicity because big dosage is up front
What can food do to drug
intereferes with dissolution and absorption of certain drugs (Speeds up or slows down)
What is pharmmacokinetics
Process of drug movement through the body to achieve drug action
What is the accronymn for pharmacokinetics and what does it stand for
ADME: Absorption, distribution, metabolism, and excretion
What is absorption and what does it depend on?
Process by which the drug is available for use in the body (how it goes from the GI tract into the body and the fluidds), it depends on how it enters the body and how it is prepared.
What are the 3 processes of absorption
Passive, active and pinocytosis
Where are most drugs absorbed
surface area of the small intestine (through the action of the villi)
What is passive absorption
from high to low concentration,
does not take energy
(Ex: 1st time meeting family, husband ends up in laundry rroom ::)
What is active absportion
It requires energy in the form of a carrier like an enzyme or a protein.
(can go from lower to higher but needs energy to do so.)
Ex: taking your hand to dance...
Define pinocytosis
ENGULF
(cells carry the drug across the membrane by engulfing)
Ex; Carrying somebody across the dance floor
Name 7 things that affect absorption
blood flow
pain
stress
hunger
fasting
food
ph
How can blood flow affect absorption
vasoconstriction
exercise
shock
How can food affect absorption
slow or speed up affect
(Solid, hot, or fatty-->slows gastric emptying time)
What slows gastric emptying time,
what does that do with drug absorption
pain stress or foods, slows absorption rate
What affect does exercise have on drug absorption
decreases blood flow to peripheral muscles thus slowing absorption
Which muscle has the fastest absorption
deltoid (Most blood vessels and is smaller)
At what rate does subQ tissue absorb drugs
slowly,
less blood vessels
(Ex: insulin and heparin, it is in the fatty tissue so it's absorbed slower through this area)
What are 2 things that affect the drug absorption in children
gastric ph,
and skin
(thinner skin-->topical=more systemic)
What is the pH of a neonate and when do they start produucing acid
alkaline at birth,
1-2 months is when they start producing acid
What affect does low pH have on drugs
absorbed faster in low pH
(acidic environment)
When do children get to adult stomach acidity
1-3 years old
What do you need to watch for with topical drugs on children
what for overdose,
because absorption is enhanced (systemic affect)
Name 3 things that change the absorption in geriatrics
decrease in gi motility and blood flow = slows it,
Increase alkaline gastric secretions (Entertic coated break down faster)
The amount of drug absorbed is not affected by age but by the environment
(Ex: different ages are different in different people A.K
What is the Gi membrane mostly composed of?
fat and protein?
How fast do lipid-soluable drugs pass through a lipid membrane
Fast (fat+fat=friends!)
What do water-soluable drugs need to pass through a cell membrane
Need a carrier
(enzyme or protein)
What ionization passes through cell membranes
Non-ionization (neutral)
What drugs pass through cell membrane the fastest
Lipid soluable and non-ionized
(vs water soluable and ionized-->need carriers)
What must you keep in mind when you give drugs that go through the first pass affect?
Larger dose because liver will neutralize some of it.
What are 2 examples of first pass affect
coumadin and morphene
what is bioavailability
% of administrated dose that reaches systemic circulation.
(which is available after the binding)
How much of a drug is absorbed PO
Less than 100%
How much drug is absorbed through first pass affect
20-40% (dose usually 3x greater)
How much drug is absorbed through IV route
100%
What 5 factors alter bioavailability
drug form
route of administration
gi mucosa/motility
food and other drugs
changes in liver metabolism
what happens to drug absorption when liver function decreases
Decreases
(only if the drug is metabolized by the liver!)
what is distribution
Systemic circulation to target sites
(like a train that goes from systemic to localized)
What do drugs do during distribution
interact with specific receptors
what happens to drugs when organ blood flow increases
receives medication faster
What must happen to the blood level to make the drug effective
The blood level must be maintained
(so the drug level doesn't have to increase or decrease ex:antibiotics)
What differences in children change drug absorption
more water less fat
(opposite of elderly)
How much of a premature baby is made up of water
85%
How much of a neonate or infant is made up of water
70%
How much of an older child is made up of water
50-60%
What does increased water in a child mean?
increase in body fluids that allows for more of a drug to be diluted
(decreases concentration of the drug FYI until age 2 higher doses of water soluable medication)
What must you know about fat in children when talking about fat soluable drugs
decrease the dose because they have less fat
(fat-soluable drugs saturate fat tissue first before acting on body tissues)
How do you know whether drugs are high protein or low protien bound drugs
if more than 89% high protien
if less than 30% of a drug is bound to protein it is low protein bound
What do protein bound drugs bind to specifically:
primary albumin and globulin in blood plasma
What happens to protein bound drugs when circulation decreases
More bound drug is released from the protein to maintain balance
(water going down, in boat, get rid of people.. :)
When can drug toxicity happen in protein binding
when 2 types of protein-bound drugs fight for proteins thus causing more free drug to be released... Low protein level=less protein to bind to=more free drug
What must you do if you are giving protein binding drugs
check pt plasma protein and albumin levels
What is the difference in neonates and infants with protein bound drugs and what does this mean?
They have less albumin and protein receptor sites... Allows medication to be more available for use and it causes a decrease in needed dosage
What are the difference in geriatric pt with protein bound drugs and lipid or water soluable drugs and what does it cause
Loss in protein bind sites=increased free drugs and chance for adverse reactions...
loss of body water=water soluable drugs become more concentrated...
increase body fat= more drug absorbed in fat and decrease in desired drug affect
What is drug metabolism
Process by which drug is converted by the liver to an inactive metabolite or water soluble substances for excretion
where can drugs be metabolized
LIVER
lungs, kidneys,
What can some drugs be transformed into that can increase pharmalogical responses
Active metabolites
What must you do for patients with decreased liver function because of a metabolism and what will they require
liver tests, lower dosage
What is metabolism dependent on in children?
Maturation not age (same as elderly)
What must you know about children's ability to metabolize drugs?
Until 2 years old children have decreased hepatic enzymes making a slower metabolism of medication.. they do have a higher metabolic rate which makes it so you must give more drug more frequently but less of it.
Why does drug metabolism decrease in geriatrics
hepatic blood flow decreases and decrease in liver size
What are the consequences of liver dysfunction in the elderly?
It decreases liver's ability to metabolize and detoxify drugs... you need to monitor liver function tests
What is LFT
Liver function test
How loong is a short half life and a long half life?
Short: 4-8 hours
Long: 24 hours
Why must you monitor kidney and liver functions, labs and I&O's, because of half life
It takes many half lives to decrease the drug to 80% and if you have difficulty excreting drugs it can cause toxicity
What drugs are secreted from the body
All inactive chemicals, by products, metabolites
What is the order of excretion?
After the liver renders the drug inactive the kidney gets rid of it
How is insoluable waste excreted
Through the GI tract by feces and bile
Where are 2 other ways of excretion?
Breast milk and sweat
What is excreted through the lungs
Anesthetic gas
What type of drug cannot be filtered through the kidneys
protein bound drugs...They must be free, unbound, and water soluable.
What urine pH infuences drug excretion
4.5-8 (neutral)
What decreases excretion time
Glomerular filtration rate
What is the most accurate test to determine renal function and what is the normal rate?
Creatanine clearance .. 85-135ml/hr
What is the creatinine clearance test
24 hour urine collection
At what age does reduced elimination capacity happen annd why does accumulation of medication happen?
Before 9 months old..
Decrease in renal blood flow, decreases in glomerular filtration rate,
reductions in renal tubular function
What must you do with children because of excretion
evaluate for dehydration
Why is excretion in geriatrics decreased
cardiac output and blood flow is decreased
What must youu watch for in geriatric pt in regards to excretion
urine output and kidney function tests..
tests: BUN, serum creatanine, creatinine clearance
What is a normal serum creatinine level
80-130ml/min
what is pharmacodynamic phase
Study of drug concentration and it's effect on the body
What is primary effect on the pharmacodynamic phasse
the desired effect=morphine for pain
what is the secondary effect in the pharmacodynamic phase
may be desirable or undesirable =
morphine respiratory depression and nausea
Why can an older pt be more or less sensitiive to drug action
age related changes in cns, in # of drug receptors, Changes in affinity or attractivenes of receptors to drugs
What is the onset of action in a drug
time it takes to reach the minimum effective concentration (MEC)
What is the peak action
when the drug reaches it's highest blood or plasma concentration
What is the duraation of action?
Length off time the drug has a pharmacological effect
How long can it take for a drug to have aan effect?
minutes to days
what does a drug agonist do?
it stimulates
What does an antagonist do?
it blocks
What does a specific drug do?
Affect one site (organ)
What does a nonspecific drug do
Affects various organs
What is an example of a nonspecific drug
cholinergic receptor,
effects occur at other cholingeric sites
(effects many sites)
What does a selective drug do
selects one receptor (key diagram)
What does a nonselective drug do
affects various receptors (key diagram)
What are examples of nonseleective drugs
norepinephrine,
dopamine,
acetylcholine,
histamine (histamine-->beta 1&2, alpha 1&2)
What does the drug action of stimulation do?
Increases rate of cell activity or secretion from a gland
What does the drug action of depression do?
Reduces cell activity and function of a specific organ
What ddoes the drug action of replacement do
Replaces essential body compounds
What does the drug action of inhibitionn or killing do?
Kills organisms..interferes with bacterial cell growth
What does the drug action of irritation do
laxatives irritate the coloon wall increasing peristalsis and defacation
What does the length of a drug action depend on?
half life of the drug and how often to give it
Drugs are seen with drug tolerance and what is it a sign of
narcotics,
alcohol,
cns depressants...
Drug dependance
What is a cumulative drug effect
When the body is not able to metabolize and excrete one dose of drug before another is given
when is cumulative drug effect seen
in liver and kidney damage causing accumulation of the drug in the body causing toxicity
What is therapeutic index
it estimates the margin of safety
What are some examples of therapeutic index
anticonvulsants,
aminoglycoside antibiotics
What is a low therapetic index
narrow safety margin-
need to monitor it closely
What is a high therapeutic index
wider saftey margin
what are peak drug levels
highest plasma concentration of a drug at a specific time
(indicates rate of absorption)
what is an oral peak drug level
1-3 hours after administration
what is an iv peak drug level
approximately 10 mins
what is an iv antibiotic peak drug level
peak levels draw-
up to 1hour after administration
what is a trough level
lowest plasma concentration drawn just before the next dose
(need a test to see this-->indicates rate of excretion or elimination)
What is a loading dose?
A large initial dose used for immediate drug response
what is a side effect
physiological affect,
not related to the desired drug affect
(can be desired or undesired,
*Body's reaction to the drug)
What is adverse reactions?
more severe than side effects ALWAYS UNDESIRABLE (mild to severe effects)
What are Toxic effects/Toxiccity
Identified by monitoring plasma (serum) therapeutic range or s/s
What is pharmacogenetics
effect of a drug action that varies from a predicted drug response because of genetic factors or heredity influences
(ex bp meds that don't effect african americans)
What is tachyphylaxis
Drug tolerance to a frequently repeated administration of a certain drug.
(Tolerant to one thing, might be tolerant to another)
What are placebo effects::
psychological benefit from a compound that may not have the chemical structure of a drug efffect
What are 3 types of drug interatcctions
drug-drug
drug-food
drug-laboratory
What is drug interaction
Only happens in the body
-an altered or modified action or effect of a drug as a result of intteraction with one+ other drug
(do not confuse with advverse reaction)
What is an adverse drug reaction
Undesirable drug effect that ranges from mild to sever effects
What is drug incompatibility
OUTSIDE THE BODY
Chemical or physical reaction that occurs among 2 or more drugs
(bind together and then expelled)
How much of warfarin is protein bound
99%
What are 2 examples of protein bound drugs
Dilantin and NSAIDs
What is an enzyme inducer
Stimulates liver enzymes
(promotes drug elimination & decreases plasma concentration)
What is an example of an enzyme inducer
barbituates
(phenobarbital-beta blockers, antipsychotics, theophylline)
smoking, chronic alcohol use, phenytoin
When does an enzyme inducer interaction occur and when does it stop
Usually interaction occurs after 1 week of drug therapy and can continue for 1 week after inducer is discontinued
What is an enzyme inhibitor
slows metabolism and excretion of certain drugs
what is a habit that can cause enzyme inhibition
acute alcohol use
How fast is the onset of an enzyme inhibitor
rapidly!
how do enzyme inhibitors effect a half life
half life of 2nd drug may be increased
(stays in body longer, effects are longer)
What must you do when giving and enzyme inhibitor
monitor drug levels
(especially if drug has a narrow therapeutic index or range)
What is an example of an enzyme inhibitor
cimetidine (Tagament)
decreases metabolism of theophylline
What do diuretics promote
water and sodium excretion
what does sodium bicarbonate cause in urine
causes it to be alkaline which promotes drugs to be excreted that are weak acids
What does alkaline urine do
promotes reabsorption of weak base drugs
(like theophylline)
What does acidic urine do
promotes excretion of urine that are weak bases
(like quinidine, morphine, atropine)
What is a pharmacodynamic interaction
the effect that 2 drugs given at the same time have on the body
What is an additive effect
sum of the effect of 2 drugs (same category)
can be desirable or undesirable
(Ex:family working together happily or not happily)
What is a synergistic effect or potentiation
Effect is greater than the combined effect of 2+ drugs from (different category)
greater than 2x the effect
Usually less meds are needed -->undesirable with alcohol
(ex: friends working together or marriage, always desirable)
What is an antagonist effect
2 drugs are combined that have opposite effects that cancel each other out.
(ex:enemies don't work well together)
Describe the drug-food interaction regarding tetracycline
when using antacids/dairy products, it binds together so tetracycline cannot be absorbed
What does monamine oxidase (MAO) do when combined with food or drugs
sympathomimetic effect=hypertensive crisis
What electrolytes can be affected during drug theraapies (4 ex's)
Potassium (K+)
Calcium (Ca++)
Sodium (Na+)
Magnesium (Mg++)
What can electrolytes can digoxin effect and what does it cause
K+,
Mg++
or increase in Ca+ which causes toxicity
(only used when benefits outweight the risk)
What can diurectiecs decrease in electrolytes
K+ or Na+
What is photosensitivity or photoallergy?
skin reaction caused by exosure to sunlight
what is photosensitivity cause?
causes cellular damage due to exposure of UVA light plus the drug
when does the reaction to photosensitivity occurs?
2-6 hrs after exposure
what % of ilnesses are treated with OTC drugs?
90%, these are unknown to healthcare providors
how much money is spent on herbal products annually
$4 billion
What is the FDA category one?
drugs are safe and effective
(green light)
what is the FDA category 2?
drugs judged to be either unsafe or ineffective FDA hasn't approved them yet
(yellow light)
what is FDA category three?
Drugs have insufficient data to asses safety or efficacy.
(red light)
what are some OTC cautions?
delay in Dx or Tx,
symptoms may be masked,
ingredients may react with other medications
Cough and cold remedies include...
most sympathomimetics used to relieve coughs and nasal and sinus congestion
what are four side effects of cough and cold remedies?
HA,
HTN,
nervousness,
insomnia
what is an active ingredient in sleep aids?
antihistamines with or without analgesics
What should be taken with sleep aids
depressants
what active ingredient was used to be used in weight control drugs?
amphetamines to suppress appetite
what is DRI vs RDA?
DRI= your DAILY reccomended dose.
RDA= percentage of that daily dose (DRI) in one VITAMIN pill
what are the four fat soluble vitamins?
KADE
mneumonic: (Kade is fat and toxic in the middle(AD)
where are fat soluble vitamins stored?
fatty tissue,
muscles,
and liver
how fast are fat soluble drugs excreted?
slowly
how fast are fat soluble vitamins metabolized?
slowly
what is the purpose of vitamin A?
maintence of epithelial tissue,
eyes,
bone,
hair
what are four adverse reactions to taking vitamin A?
teratogenic effect on fetus,
liver toxicity,
aplastic anemia,
hypervitaminosis (hair loss and peeling skin)
what are the food sources for vitamin A. (8)
whole milk,
butter,
egg,
leafy green,
yellow vegetables,
fruits,
fish,
carrots
what are three deficiencies of vitamin A
dry skin,
poor tooth development,
night blindness
what does vitamin D do
works in regulating calcium and phosphorus metabolism and is needed for calcium absorption
where to compounds of vitamin D
d2 which is synthetic and
D3 which is natural UV
what are four food sources of vitamin D
fortified milk
salmon
egg yolk
and tuna
what is an example of vitamin D deficiency
Rickits or soft bone
what are two examples of water soluble vitamin
vitamin B complex
and C
are water soluble vitamins usually toxic
no only in excessive amount
are water-soluble vitamins stored in the body and how are they excreted
no, ready to excrete
what is the function of vitamin C
aids and absorption of iron and the conversion of folic acid
what is the purpose of vitamin C
helps tissue repair and growth it is required for the formation of collagen
what do megadoses of vitamin C cause
diarrhea and G.I. upset
what can vitamin C cause with a occult and sugar test
can cause false-negative occult test and a false positive urine sugar test
what are three food sources of vitamin c
Citrus fruits
tomatoes
Leafygreen vegetables
what does deficient vitamin C cause
Poor healing
bleeding gums
and scurvy
what is the function of folic acid
body growth and
DNA synthesis
what are three deficiencies of folic acid
anemia
depression and
G.I. disturbances
what is another name for B1
thiamine
what is another name for B2
riboflavin
what is another name for B3
nicotinic acid or niacin
what is another name for B6
pyridoxine
what is the function of B12
it's in the building block of nucleic acids and forms RBC and helps with functionof nervous system
what are four foods of vitamin B 12
liver
kidney
fish and
milk
what are three deficiencies of vitamin B12
anemia
poor growth
and G.I. disorders
what does Coppe do
aids the formation of red blood cells
what does zinc do
helps in enzymatic reaction
what does chromium do
hopes of diabetes mellitus or type two
what does selenium do
anticancer
what does iron do
vitals for hemoglobin regeneration
how much iron is found hemoglobin
60%
what are six sources for iron
liver
lean meats
egg yolks
dried beans
green vegetables
and fruit
what are three symptoms of iron deficiency
fatigue
weakness
and shortness of breath
what is an adverse effect of iron toxicity
hemorrhage and shock
what are four things to teach a client about taking time
do not take with food
asorbic acid increases absorption
onset of action takes days and
keep out of the reach of children