BLOCK 5: PHARMACOLOGY Flashcards
medication vs drug
medication: substance used to treat illness/condition
drug: any substance that produces a physiologic effect
every medication is a ____ but
drug, but not every drug is a medication
scientific study of how various substances interact with or alter the function of living organisms
pharmacology
natural remedies directed toward ___, not ____
relieving symptoms not ending the disease process
what act prohibited altering or mislabeling meds
Pure Food and Drug Act of 1906
who is responsible for approving new medications and removing unsafe meds from market
US Food and Drug Administration (FDA)
Schedule 1 medication description and examples
high abuse potential, no recognized medical purpose examples: heroin, marijuana, LSD, peyote
Schedule 2 medication description and examples
high abuse potential, legitimate medical purpose
examples: opioids (codeine, fentanyl, hydrocodone, morphine) and stimulants (amphetamine, adderall, cocaine, meth, ritalin)
Schedule 3 medication description and examples
lower potential abuse than schedule 2
examples: opioids (acetaminophen with codeine like tylenol) and nonopioids (anabolic steroids, ketamine)
Schedule 4 medication description and examples
lower potential abuse than schedule 3
examples: alprazolam (xanax), diazepam (valium), lorazepam (ativan)
Schedule 4 medication description and examples
lower potential for abuse than schedule 4 drugs
examples: opioid cough medicines
what three things do all schedule 2 through 5 medications require
locked storage, detailed record keeping, and controlled wasting procedures
powdered or solid medication enclosed in a dissolvable cylindrical gelatin shell
capsule
solid medication particles bound into a shape designed to dissolve or be swallowed
tablet
small particles of medication designed to be dissolved or mixed into a solution or liquid
powder
sterile solution or nonsterile liquid intended for direct administration into the nose or ear
droplet
sterile solution for direction injection into a body cavity, tissue, or organ
parenteral solution
gel, ointment, or paste substance designed to permit transdermal absorption
skin preparation
medication in a wax like material that dissolves in the rectum or other body cavity
suppository
medication dissolved or suspended in liquid intended for oral consumption
liquid
medication in gas or fine mist form intended for inhalation and absorption through the lung, airway, or oral tissues
inhaler/spray
what is a chemical name of a medication
long and difficult to pronounce that indicate medication’s chemical composition during initial development
what is the generic or nonproprietary name of a medication
include a “stem” that links them to other meds in the same drug class
what is a brand name for a medication
for marketing purposes and sometimes linked to a particular condition that medication treats for
what is “tall man” lettering
capitalized letters highlight portion of name in meds with similar names
3 parts of pharmacokinetics
onset, peak, and duration (of action)
what is the onset of pharmacokinetics
estimated amount of time it will take for medication to enter the body/system and take effect
what is the peak of pharmacokinetics
estimated amount of time it will take for the medication to have its greatest effect on the patient/system
what is the duration of action of pharmacokinetics
estimated amount of time that medication will have any effect of the patient/system
what is pharmacodynamics
mechanism of action - the way in which a medication produces the intended response
do pediatric and older patients have slower or faster medication absorption and elimination times
slower
“package inserts” with every medication provide what 5 components
dosing, route of administration, contraindications, adverse effects, and characteristics of medication
class I interventions
strong evidence supports use, benefit greater than risk, intervention should be performed
class IIa interventions
moderate evidence that benefit is greater than risk, intervention is reasonable and may be useful
class IIb interventions
weak evidence that benefit is greater than risk, intervention may be considered
class III no benefit interventions
evidence is weak, benefit equals the risk, intervention should not be performed
class III harm interventions
strong evidence that risk is greater than benefit, intervention should not be performed
what are endogenous chemicals
those occurring naturally within the body and by the presence of meds and chemicals absorbed in the body
where are receptor sites
in proteins connected to cells throughout the body
four possible actions that occur when medication binds with a receptor site
- channels in cell walls are opened or closed
- biochemical messenger actives and initiates other chemical reactions within cell
- normal cell function is prevented
- normal or abnormal function of the cell begins
children who ingest mouse poisons will exhibit effects similar to the administration of ____
warfarin (coumadin)
agonist medications
initiate or alter cell activity by attaching to receptor sites to prompt a response
antagonist medications
prevent agonist chemicals from reaching cell receptor sites
what is affinity
the ability of medication to bind with a particular receptor site
what two things affect the number of receptor sites bound by a medication
affinity and concentration
increasing concentrations of medications cause increased effects until what
all receptor sites become occupied or max capability of cell is reached
what is potency
concentration of medication required to initiate a cellular response
as potency of medication increases, what decreases
concentration or dose required for a response
what is efficacy
the ability to initiate or alter cell activity in a therapeutic or desired manner
what is the dose-response curve
relationship between medication dose/concentration and efficacy
competitive vs noncompetitive antagonists
competitive: temporarily bind with cell receptor site to displace agonist chemicals
noncompetitive: permanently bind with receptor sites and prevent activation by agonist chemicals until new receptor sites or cells are created
partial agonist chemicals
bind to receptor site but do not initiate as much cell activity or change as other agonists
lower efficacy of other agonist chemicals
two types of microbials what they do
antibiotics and antifungals - target specific substances present in cell walls of certain bacteria or fungus
what are chelating agents
bind with heavy metals like lead, mercury and arsenic in body to create a compound that can be eliminated
what are diuretic medications
distribute into water in the body to create osmotic changes that alter distribution of fluids and electrolytes - draws excess water from body tissues and enhances urine excretion
what three types of body tissues do meds become distributed into
water, lipids/fats, and proteins
water-soluble medications are administered differently to what population and how
higher weight-based doses to infants because they have higher percentage of body water
fat and lipid-soluble medications are administered differently to what population and how
higher weight-based doses in older adults because of their higher body fat percentage and increased fat distribution
medication metabolism in the liver is affected by the what
cytochrome P-450 system
what are paradoxical medication reactions
clinical effects opposite to the intended effects of the medication
two risks that come with weight-based dosing
improperly estimating patient weight
wrong multiplication of numbers in a formula
ideal body weight formulas in kg for men and women
men: 50 + (2.3 times patient’s height in inches over 5ft)
women: 45.5 + (2.3 times patient’s height in inches over 5ft)
how does hyperthermia affect medication absorption, metabolism, and efficacy
increases hepatic blood flow which increases metabolism of drugs in the liver reducing amount of drug returned to circulation
suppresses function of the cytochrome P-450 which decreases rate of metabolism
how does hypothermia affect medication absorption, metabolism, and efficacy
impairs effectiveness of medications
what increases and what decreases during pregnancy
increases: cardiac output, intravascular volume, tidal and minute volume, urinary output
decreases: hematocrit (% of RBCs), GI motility, resp reserve volume
error/delay in diagnosis, failure to use indicated tests, outdated tests/therapy, failure to act
diagnostic medical error
treatment medical error
error in performance of operation, procedure, test, error in administration, in dose/method, avoidable delay, inappropriate care
preventative medical error
failure to provide prophylactic treatment (preventative) and inadequate monitoring or follow-up of treatment
other type of medical error
failure of communication, equipment failure, or other system failure
what is cumulative action
several smaller doses of med produces same effect as large dose of same med - can decrease risks of too much administered
the vast number of receptor sites within the body make medications ___ rather than ____
selective, specific
side effect is aka ____
adverse affect but adverse is more harmful
adverse effects are aka ____
untoward effects
what is an exaggerated therapeutic effect
undesired/harmful responses directly related to the intended response (bradycardia after taking metroprolol)
two groups of meds susceptible to abuse
stimulants and depressants
what are stimulants and examples
increase in physical, mental, and emotional performance
increase in LOC, HR, BP, and sympathetic nervous system
ex. caffeine, coke, amphetamines
what are depressants and examples
cause sedation, anxiolysis (decrease of anxiety) and decreased RR, HR, BP
reduce sympathetic nervous system
ex. alcohol, benzos, opioids
what is habituation
abnormal tolerance to effects of a substance
what is dependence
physical, emotional, or behavioral need for substances to maintain “normal” level of function
what is medication interference
undesirable medication interactions
the onset and peak of a medication are generally related to ___ and ____
absorption and distribution
the duration of medication effect is generally related to ___ and ____
metabolism and elimination
what is an addition or summation med interaction
two meds with similar effect combine to produce an effect equal to the sum of each individual effect
what is synergism med interaction
two meds with similar effect combine to produce effect greater than sum of med’s effects
what is potentiation med interaction
effect of one med is greatly enhanced by presence of another med that does not produce the same effect
what is altered absorption med interaciton
action of one med increases/decreases ability of another med to be absorbed in the body
what is altered metabolism med interactions
action of one med increases/decreases the metabolism of another med within the body
what is altered distribution med interaction
present of one med alters area available for the distribution of another med in the body (when both meds are bound to the same site)
what is altered elimination med interaction
meds may increase/decrease the functioning of kidneys or other route of elimination, influencing amount/duration of effect of another med in the body
what is physiologic (drug) med interaction
two meds with opposite effects are present simultaneously which result in minimal or no changes
what is neutralization med interaction
two meds bind together in the body to create an inactive substance
what is bioavailability
the percentage of the unchanged medication that reaches the systemic circulation
meds administered by IV have what percent bioavailability
100%
many meds prescribed for chronic med conditions and prehospital meds are administered where
into the GI system
what factors affect GI med absoprtion
GI motility (ability of med to pass through GI tract into bloodstream)
GI pH (perfusion of the GI tract that can be decreased during shock or trauma)
presence of food, liquids, or chemicals in stomach
what can happen to GI medications in first-pass metabolism
med goes from GI tract into the liver, metabolism occurs, and can alter or inactivate medication before it reaches circulation
why are oral doses higher than IV doses
they take into account first-pass metabolism
who are oral doses dangerous for
people with liver dysfunction are at risk because first-pass effect is impaired so they can get toxic amounts
if endotracheal route is used instead of IV, how do you adjust the dose of medication
2-2.5x IV dose followed by 5-10mL flush
bioavailability of intranasal medications
close to 100%
what is the preferred method of administering meds in prehospital setting
IVs
what medication classes are significant concern if infiltration into tissues around blood vessels and why
sympathomimetics and electrolyte solutions because they cause significant pain and tissue damage
what vein is used in proximal tibia IO
popliteal vein
what vein is used in femur IO
femoral vein
what vein is used for distal tibia (medial malleolus) IO
great saphenous vein
what vein is used for proximal humerus IO
axillary vein
what vein is used for manubrium (sternum) IO
internal mammary and azygos veins
what are contraindications for IOs
fractured bones or bone diseases/skin infection over insertion site
bioavailability of IM medications
75-100%
what do transdermal patches do
deliver constant dose of medication over an extended period
what is the bioavailability of sublingual meds and how is the dose changed compared to IV
very low, close to 100x larger than IV dose
nebulized meds have the potential to cause what
bronchospasms
what is the bioavailability of rectal medications and why is it higher than oral medications
greater than 90%
it is not subject to first-pass metabolism
how do nonionic and lipophilic molecules enter the cell
easily passing through cell membranes
how do hydrophilic and ionic molecules enter the cell
through pinocytosis and binding with carrier proteins
what three barriers prevent medication molecules from passing through capillary walls
blood-brain, blood-placenta, and blood-testes
how does plasma protein-binding affect medication distribution
med molecules attach to proteins in blood plasma to circulate around body
if another protein bound-medication with a greater affinity is administered, it can displace the first med, giving the patient toxic effects
what is the volume of distribution
the extent to which a med will spread within the body
what is a metabolite
medication undergoing biotransformation
active vs inactive metabolites
active: main capable of some pharmacologic activity
inactive metabolites: no longer possess ability to alter cell process or body function
where does most biotransformation occur
in the liver
suspect altered medication metabolism in patients with what
chronic alcoholism, liver disease, or any liver condition
medications and other chemicals are primarily removed from the body by the ___
kidneys
zero-order vs. first-order elimination
zero: fixed amount of substance is removed during a certain period regardless of total amount in body
first: plasma levels of substance directly influence rate of elimination
first-order elimination is quantified as what
the medication’s half-life
the 9 rights of medication administration
right patient
right med and indication
right dose
right route
right time
right patient education
right to refuse
right response and evaluation
right documentation and reporting
alpha 1 agonist effect
constriction of arteries, vascular smooth muscle, bladder, and GI
alpha 2 agonist effect
stop pancreatic enzyme and insulin release, suppress norepinephrine release, stop GI motility
beta 1 agonist effect
(heart) increase heart ate, contractility, and conduction
beta 2 agonist effect
(lungs) bronchodilation, stop insulin release, increase glucagon release, relaxation of intestines, bladder, uterus
beta 3 agonist effect
increase lipolysis and heat production in fat
dopaminergic agonists effect
memory, attention, impulse control, regulation of renal function, locomotion, learning, sleep, decision making
dopaminergic 2 agonist effect
locomotion, attention, sleep,
nicotinic agonist effect
allow acetylcholine to stimulate muscle contraction
muscarinic 1 agonist effect
cognition, arousal, gastic acid secretions
muscarinic 2 agonist effect
cardiac - decrease heart rate and contractility
muscarinic 3 agonist effect
stimulate gland secretion and smooth muscle contraction
muscarinic 4 agonist effect
act on potassium and calcium channels
muscarinic 5 agonist effect
affect dopamine release
opioid Mu agonist receptors
most prominent, greatest affinity for morphine and naloxone
causes analgesia, sedation, mood changes, constricted pupils , respiratory depression, decreased GI motility
opioid delta agonist receptors
spinal analgesia, respiratory depression, decreased GI motility
opioid kappa agonist receptor
spinal analgesia, sedation, dysphoria, decreased GI motility
alpha agonists cause vaso___
beta agonists cause vaso___
in arteries
constriction
dilation
alpha agonists cause broncho___
beta agonists cause broncho___
bronchoconstriction (very little)
bronchodilation
which receptors are in lungs, heart, and arteries?
lungs: beta 2 and alpha
heart: beta 1 only
arteries: alpha and beta
drugs that act primarily on cardiac beta receptors are called what
beta-1 adrenergic agonists
drugs that act primarily on pulmonary beta receptors are called
beta-2 adrenergic agonists
what do beta adrenergic blockers do
occupy beta receptors in heart, lungs, and arteries so beta agents can’t exert their full effects
what are etomidate and ketamine used for
short-acting sedative meds to facilitate airway placement
what are benzodiazepines used for
seizures, anxiety, sedation
what can benzodiazepines cause at high doses
hypotension
what are benzodiazepines classified as in related to pregnancy
class D - potential to harm fetus
two classes of chemical paralytic agents
deplarizing and nondepolarizing
what are chemical paralytic agents used for
muscle relaxation for airway device placement
how do paralytic agents work
bind with nicotinic receptor sites of muscles to prevent activation by ACh
difference between depolarizing and nondepolarizing paralytics and examples of each
depolarizing: ACh receptor agonists activate the receptor sites (succinylcholine)
nondepolarizing: competitive antagonists to ACh, do not activate the receptor sites (rocuronium and vecuronium)
what are beta agonist medications used for
acute bronchospasms related to COPD and asthma
what are corticosteroid medications used for
reduce airway inflammation to improve oxygenation and ventilation
what are leukotrienes
patients with asthma have an overproduction of these
they bind to receptor sites in lungs and cause powerful bronchoconstriction
what are leukotriene receptor antagonist medications used for
taken by patients with asthma and allergies on a long-term basis
what is ectopic foci
site of electrical impulse generation other than normal pacemaker cells
what are antidysrhythmic mecications used for
target heart cells to resolve dysrhythmia and suppress ectopic foci
what is the Vaughan-Williams classification scheme
breaks down the meds used to treat cardiac dysrhythmias into four classes based on mechanism of action
5 phases of cardiac cell activity
phase 0: cardiac muscle cell receives an impulse, sodium enters cell and depolarization occurs
phase 1: sodium channels close and potassium exits cell
phase 2: sodium and calcium enter the cell and potassium exits the cell, repolarization begins
phase 3: calcium channels close and calcium leaves cell while potassium channels open, repolarization ends
phase 4: cardiac cells are at rest waiting for impulse
what do class 1 antidysrhythmic medications do
slow the movement of sodium through channels in certain cardiac cells - potential to prolong QRS and QT intervals
what do class 2 antidysrhythmic medications do
also known as beta adrenergic blocking agents (beta blockers)
completely stop catecholamine (epi and norepi) activation of beta receptor sites
what do class 3 antidysrhythmic medications do
increase duration of phases 1,2, and 3
prolong absolute refractory period, treating atrial and ventricular tachycardias
what do class 4 antidysrhythmic medications do
displace calcium at receptor sites or enter smooth muscle cells in place of calcium
reduces BP, controls HR, increase oxygen to heart during ischemia
what is down-regulation
tolerance resulting from mechanism that reduces number of cell receptors available for binding with particular medication
what is median toxic dose
50% of tested animals had toxic effects
anaphylaxis occurs with which exposure to an allergen
the second
what is cross-tolerance
repeated exposure to a med within a particular class causes tolerance to other meds in same class
what is median lethal dose
50% death rate in animal testing
which medications are the primary culprits of immune-mediated responses
aspirin, penicillin, and sulfa-based antibiotics
what can antiseizure medications cause
Stevens-Johnson syndrome (mimics a burn)
what is therapeutic index
relationship between median effective dose and median lethal or toxic dose
what is tachyphylaxis
giving repeated doses of medication within short time frame can rapidly cause tolerance making the medication ineffective
what is adenosine
the only fifth class antidysrhythmic medication
used to treat stable, regular narrow QRS tachycardia and for unstable QRS tachycardia for cardioversion
what can antidepressant medications cause
cardiomyopathy
what are idiosyncratic medication reactions
adverse effects completely unexpected and not previously known
what do alpha adrenergic receptor antagonists do
aka alpha blockers
prevent endogenous catecholamines from reaching alpha receptors in smooth muscle of blood vessels
lower diastolic BP and systemic vascular resistance
patients taking alpha blocking meds are susceptible to what
orthostatic hypotension
what do angiotensin-converting enzyme inhibitors do
aka ACE inhibitors
alter renin-angiotensin system
reduces BP and cardiac afterload in pt’s with hypertension, cardiomyopathy, and heart failure
patients who take ACE inhibitors may experience what
chronic dry cough
what do anticholinergic medications do
used on people exposed to acetylcholinesterase inhibitors in pesticides and nerve agents
stops ACh from activating muscarinic-2 receptors
allows sympathetic stimulation to take over hyperactive vagus nerve of parasympathetic system
what do catecholamines do
natural occurring chemicals in the body - cause “fight-or-flight”
mimic epi, norepi, and dopamine
what does epi stimulate
alpha, beta-1 and beta-2
what does norepinephrine stimulate and when is it used
alpha and beta-1 (alpha is stronger)
sepsis, neurogenic shock, anaphylactic shock
what is dopamine used for
hypotension refractory to volume resuscitation
what is dobutamine and its uses
synthetically manufactured catecholamine similar to dopamine
activates beta 1 and 2 and alpha sites
treats cardiogenic shock
what do digitalis preparations do
increase the strength of cardiac contractions
prescribed for chronic heart failure and rapid atrial dysrhythmias
what are patients taking digitalis preparations sensitive to
calcium and potassium levels
what three major classes of drugs are used to relieve angina pain
nitrates, beta blockers, calcium channel blockers
what are direct vasodilator medications used for
management of hypertension, heart failure, MI, cardiac ischemia, cardiogenic shock
cause vascular smooth muscle relaxation and vasodilation
what are diuretics used for
eliminate certain toxins from the body and to promote excretion of excess electrolytes
the average adult has __L of blood, making up ___ percent of body weight
5
7-8%
unmatched blood transfusions are almost always type ___
O, Rh negative
what are packed RBCs used for
to correct anemia from blood loss, inadequate RBC production, or hemolysis
what are patients who receive PRBCs at risk for
hypocalcemia and hyperkalemia
what is fresh frozen plasma used for
replacement of clotting factors NOT volume expansion
what are platelets used for
to correct thrombocytopenia (low platelet level in blood)
what is tranexamic acid used for
made of lysine amino acid that promotes blood clotting in trauma patients
what are anticoagulant medications used for
impair function of clotting to treat/prevent acute coronary syndrome, deep vein thrombosis, and pulmonary embolus
what are antiplatelet medications used for
reduce platelet aggregation (clumping) preventing new thrombus formation or extension of an existing one
what are fibrinolytic drugs used for
dissolve blood clots in arteries and veins
what are phenytoin and fosphenytoin used for
limit sodium in CNS by altering channels to prevent seizure activity
what are histamine 2 receptor agonists used for
decrease acid secretion in the stomach for protection against ulcers, GI bleeding, and acid-aspiration pneumonitis
what is a Mallory-Weiss tear
tear in mucous membrane of the lower esophagus or upper part of stomach
what are antiemetic medications used for
prevent or treat nausea and vomiting
what is octeotride used for
decreases blood flow to esophagus to reduce bleeding
stops release of serotonin, insulin, glucagon, GH
what is acetaminophen used for
(tylenol) antipyretic and mild analgesia
for preventing febrile seizures
what are calcium preparations used for
reverse calcium channel blocker OD
treat magnesium toxicity
prevent hyperkalemic dysrhythmias
what is dextrose used for
hypoglycemia
what is diphenhydramine used for
anaphylaxis, allergic reactions, mild sedative and cough suppressant
what is glucagon used for
hypoglycemia in patients you cant establish an IV in
what is ketorolac used for
(toradol) treats pain and inflammation
what is magnesium sulfate used for
treatment of torsades de points or similar ventricular dysrhythmias
treatment of seizures for patients with pre or eclampsia
what is sodium bicarb used for
raise blood pH in patients with metabolic acidosis, stabilize hyperkalemia, promote urinary excretion
what is tetracaine used for
mild ophthalmic anesthetic for inserting Morgan lens into an eye for flushing the eyes
what is thiamine used for
commercial version of vitamin B1 for those with a deficiency from malnourishment or chronic alcoholism before dextrose administration
prohibited altering or mislabeling meds
The Pure Food and Drug Act
Parkland formula
fluid amount for burns
4mL x kg x burn %
lipophilic vs lipophobic drugs
lipophilic: dissolve in fats (go thru cell membrane)
lipophobic: don’t dissolve in fats (need carrier protein to cross into cell membrane)
7 P’s for RSI
preparations
preoxygenation (to 95%)
pretreatment/priming (getting equip. ready/dosing)
paralytic/sedation (sedation BEFORE paralytic)
pass the tube
prove it (capno, lung sounds, chest rise)
post-intubation management (maintain sedation/oxygen)
