Exam 1 Flashcards
absorption
transmission of drug from site of administration to bloodstream
rate of absorption
how soon the medication takes effect
What determines how strong the effect of a medication will be?
amount absorbed
What affects the rate and amount of absorption?
route of administration
oral/enteral medication barriers to absorption
- must pass through GI epithelial layer
- swallowing ability
What factors influence absorption of oral and enteral medications?
- solubility and stability of drug
- GI pH
- GI contents
- gastric emptying time
- form of medication (enteric coated, ER, etc.)
advantages of oral or enteral medications
- safe
- inexpensive
- easy to administer and take
- convenient
disadvantages of oral or enteral medications
- highly variable absorption
- first-pass effect
- client must be conscious, willing, able
- can’t give if pt has N&V
nursing implications of oral or enteral medications
- do not give if pt:
- can’t swallow
- has no gag reflex
- has N&V
- isn’t conscious
- pt in high Fowler’s unless contraindicated
- unless otherwise instructed, give on empty stomach: 1 hr AC or 2 hrs PC
- administer irritating meds with very small amount of food (NOT GRAPEJUICE or other interacting foods)
- follow manufacturer instructions about crushing, cutting, etc.
- liquid if pt can’t swallow pills
- follow instructions on diluting
- measure at base of meniscus
How do sublingual and buccal medications absorb?
rapidly through highly vascular membrane
barriers to absorption of sublingual and buccal medications
swallowing before dissolved–gastric pH can inactivate medication
nursing implications for administration of sublingual and buccal medications
- instruct pt to keep med in place until completely dissolved
- pt should not eat or drink while med is in place
How are suppositories absorbed and what type of effect can they have?
- easily absorbed by intestinal or vaginal wall
- local or systemic effects
barriers to absorption of suppositories
presence of stool or infection can limit absorption
pattern of absorption for inhaled medications
rapidly through alveolar capillary network
barriers to absorption of inhaled medications
inspiratory effort
pattern of absorption for topical and transdermal medications
- slow
- local or systemic effects
barriers to absorption of topical and transdermal medications
epidermal cells are closely packed
What factors affect absorption of topical and transdermal medications?
- placement: fat vs muscle tissue
- tissue quality
- age: infants absorb more readily than older children, adults
What instructions do you give a patient using a transdermal medication?
- don’t alter dosing schedule
- wash skin with soap and water and dry
- remove old patch before applying new
- rotate sites to avoid skin irritation
- use hairless area
what to remember when applying topical medications
ALWAYS use a glove to avoid absorbing pt’s medication
What factors affect the rate of absorption of IM meds?
- solubility of med in water: more soluble = faster absorption
- perfusion at injection site: higher = faster
barriers to absorption of IM medications
no significant barriers
pattern of absorption for IV meds
- immediate and complete
- directly into bloodstream
barriers to absorption for IV meds
none
distribution
transmission of drug from bloodstream to site of action
What factors affect distribution of a drug?
- traffic
- perfusion
- physical barriers
- speed
- exits: ability to travel between capillary cells
- binding
- binder needed?
- binder available?
- competition for binder?
most common protein needed for plasma protein binding
albumin
What lab might we check for certain drugs to ensure distribution?
serum albumin
free drug
- unbound med in bloodstream
- can lead to toxicity
How would insufficient serum albumin affect the distribution of one or more protein-bidning drugs?
- one drug: could lead directly to toxicity for lack of binding sites
- two or more: drugs compete for binding sites, and somebody gets left out, leading to toxicity
barriers to distribution of medications
- low albumin/malnourishment (for protein-binding drugs)
- BBB and placental barrier: only fat-soluble meds can get through
- BBB not fully developed at birth; can lead to neurotoxicity
metabolism of drugs
- biotransformation
- how the drug is broken down into less active or inactive form
What factors affect metabolism of drugs?
- age
- infants have limited metabolic capacity
- older adults have lower hepatic metabolic capacity
- less drug
- increased enzymes
- rapid metabolism
- more drug
- first-pass effect
- oral meds pass through liver first and become inactive
- more drug
- similar meds
- some metabolized through same pathway
- pt could have toxicity of one
- nutritional status
- malnourishment affects production of enzymes, impairs metabolism
- less drug
excretion
how drug is eliminated from body after metabolism
How are drugs excreted?
- primarily through kidneys
- also through sweat glands, GI tract, etc.
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What affects excretion of a drug?
- kidney dysfunction
- lower dose needed
What lab values do we monitor for excretion?
- BUN
- creatinine
agonist
- drug that increases an action
- bind or mimic receptor activity of endogenous compounds
antagonist
- blocks an action
- blocks normal receptor activity regulated by endogenous compounds
half-life
time it takes for drug in the body to be reduced by half
short half-life
- drug leaves body quickly (4-8 hrs)
- more frequent dosing required
long half-life
- leaves body slowly
- less frequent dosing
- takes longer to reach plateau
therapeutic range
serum level of drug in which it produces a therapeutic effect without causing toxicity
plateau
- med’s plasma concentration during a series of doses
- should be inside therapeutic range
minimum effective concentration
lowest serum level of drug that produces a therapeutic effect
toxicity
serum level higher than the therapeutic range that negatively affects body function
therapeutic index
safety margin between minimum effective concentration and toxicity
low therapeutic index
requires close monitoring of plasma levels to ensure effectiveness and pt safety
high therapeutic index
- wide safety margin
- no frequent monitoring
tolerance
- body’s decreased response to a drug over time
- higher dose required to achieve therapeutic effect
dependence
- mental or physical state in which a person is compelled to take a drug continuously or periodically to experience its effects or avoid discomfort of its absence
- tolerance may be present
- can be dependent on multiple drugs
- withdrawal symptoms possible
process for instilling eye drops
- use surgical aseptic technique
- client upright or supine, head tilted slightly, looking at ceiling
- dominant hand resting on forehead, holding dropper 1-2 cm over conjunctival sac
- nondominant hand on cheekbone, pulling downward to expose conjunctival sac
- drop med into center of sac
- have client close eye gently
- FOR SOME MEDS: apply gentle pressure to nasolacrimal duct for 30-60 sec to prevent systemic absorption
process for instilling ear drops
- use medical aseptic technique
- client upright with head tilted or side-lying
- straighten ear canal: pull auricle up and out for adults, down and back for children younger than 3 yrs
- hold dropper 1 cm above canal, instill med
- press gently on tragus
process for instilling nose drops
- use medical aseptic technique
- pt supine with head slightly tilted and extended
- support head with nondominant hand
- hold dropper 1.5 cm above nostril with dominant hand and instill drops
- instruct pt: breath through mouth, stay in position, avoid blowing nose for 5 min
process for applying eye ointment
administering any suppository
- follow manufacturer instructions for storage
- wear glove
- remove wrapper and lubricate
administering rectal suppository
- pt in left lateral/Sim’s
- insert just beyond anal sphincter
- instruct pt: retain med for 30-60 min for stimulation of defecation or 60 min for systemic absorption
- pt supine with knees bent, feet flat and close to hips
- generally inserted with applicator
- pt instruct: remain in position for prescribed amount of time
administration of MDI inhaled medication
- shake
- deep breath in and out
- tilt head back a little
- spray inhaler into mouth and take 3-5 second breath in
- hold breath 10 seconds
- slowly exhale through pursed lips
- breathe normally
administering MDI inhalation med with spacer
- spacer lets more med get to lungs, less stuck in oropharynx
- insert spacer at end of MDI
- shake
- use same as MDI without spacer
administering DPI inhalation medication
- DO NOT SHAKE
- follow manufacturer instructions for prep
- inhaled just like MDI
administration of IM injection
- appropriate for irritating meds, those in oil, aqueous suspensions
- common sites
- ventrogluteal
- vastus lateralis
- deltoid
- needle size 18-27 (usually 22-25), 1-1/5 in
- volume usually 1-3 mL; divide into separate injections if more
- Z-Track
- prevents med from leaking into SC tissue
- often for meds that cause skin stains (e.g. iron)
administering IV medications
- for medications, fluids, blood products
- IV catheters for short-term
- infusion ports for long-term
- trauma: 16-gauge
- surgical: 18-gauge
- children, older adults, medical, stable post-op: 22- to 24-gauge
- adult peripheral preferred sites: arm or hand; ask client which side
- neonate sites: head, lower legs, feet
- after admin, immediately monitor for therapeutic and side/adverse effects
intrathecal med administration
admin of IV opioid analgesia
infusion pump necessary
epidural: catheter
intrathecal is injection only
advantages of IM and SC injection
- good for meds poorly absorbed in GI tract
- good for meds meant for slow absorption over extended period
disadvantages of IM and SC injection
- more expensive
- inconvenient
- painful
- risk of tissue/nerve damage
- risk of infection
advantages of IV medication
- rapid onset
- control of amount given
- allows for larger volumes
- can dilute irritating meds
disadvantages of IV administration
- very expensive
- requires skilled admin
- higher risk of med error having drastic consequences
- increased infection risk
List the necessary components of a prescription.
- pt full name
- date and time of Rx
- name of med
- strength and dosage
- route of admin
- time and frequency: exact times or number of times per day
- quantity to dispense and number of refills
- signature of provider
Describe the process of medication reconciliation.
- compile list of current meds with dosages and frequency
- compare list with new prescriptions
- consult with provider to resolve discrepancies
- occurs at admission, transfer, and discharge
List the six (seven) rights of medication administration.
- right pt
- right drug
- right dose
- right time
- right route
- right documentation
- (right of refusal)
common medication errors
- wrong med or IV fluid
- incorrect dose or IV rate
- wrong client, route, or time
- admin of allergy-inducing med
- omission of dose or admin of extra doses
- incorrect DC of med or IV fluid
- inaccurate prescribing
- incorrect med: similarly named
nursing responsibilities when administering drugs
- know about meds administered
- get info about diagnoses and conditions that affect admin
- get necessary preadministration data (VS, baseline data) for evaluation and to assess appropriateness
- omit or delay doses due to pt status
- determine if Rx is complete
- interpret Rx accurately
- question provider if Rx is unclear or seems inappropriate
- question abrupt and excessive med changes
how to document med errors
- document facts
- fill out facility paperwork
- don’t mention facility paperwork in chart
how to prevent med errors
- avoid distractions
- prep meds for one pt at a time
- check labels for name and concentration
- measure doses accurately, double-check with colleague
- check expiration date
- question more than two tablets or one vial
- follow Six Rights
- do not give meds someone else prepped
- teach pt about meds and to question changes
- follow correct procedures for admin
- follow all laws and regs for prep, admin of controlled substances
- don’t leave meds at bedside
- educate pt and anyone assisting (verbal and written)
side effect
- occurs when med is given at therapeutic level
- usually doesn’t require DC
adverse effect
- undesired, inadvertent, unexpected, severe response to med
- at therapeutic or higher levels
- DC drug immediately
- reported to FDA
allergic reaction
reaction resulting from hypersensitivity to an antigen
steps if you suspect an allergic reaction
- stop the medication
- notify the prescriber
- initiate lifesaving measures if needed
What do you do if a pt says they’re allergic to a med?
withhold the med
PPI mechanism of action
- blocks proton pump that exchanges H+ for potassium
- suppresses gastric acid secretion
PPI onset
up to 4 days
PPI duration
24 hrs to 3 days
PPI vs H2 blockers
- PPIs have greater acid suppression
- works on two stomach acid stimuli instead of just one
