Ch 8 Flashcards
Pharmacokinetics
how the drug is absorbed,
distributed, metabolized and excreted
Pharacodynamics
how the body is affected by the drug at the
cellular level and in relation to the target organ).
Absorbtion
refers to the passage of a medication from its site of introduction,
usually the gastrointestinal tract, into the general circulation.
Absorption of oral meds can be affected by
can be affected by
diminished gastric acid, increased gastric pH, delayed gastric
emptying and the presence of other substances (e.g., food,
nutrients, medication additives).
Elimination/serum half-life
is the time required to decrease the drug concentration by one half
of its original value.
It takes ______ half times to reach steadystate
concentrations after a drug is initiated or to completely
eliminate a drug from the body after a drug is discontinued.
5
The clearance rate
measures the volume of blood from
which the drug is eliminated per unit of time
Can herbs be taken along with medications without worry of any potential intereaction
No
How could oldr adult bod ycomposition affect the effects of medications?
decreased
body water and lean tissue and increased body fat)
can affect substances according to their degree of fat or water
solubility. Consequently, medications that are distributed
primarily in body water or lean body mass may reach higher
serum concentrations in older adults and their effects may be
more intense. Similarly, the serum concentration of highly
fat-soluble substances can increase, so the immediate therapeutic
effects are diminished, but the overall effects are prolonged
or erratic.
Polypharamacy
typically
refers to the use of more medications than are clinically indicated.
(Many drugs)
Not about the number, about the appropriateness & combination of meds
Medication nonadherence
refers to medication-taking patterns
that differ from the prescribed pattern, including missed
doses, failure to fill prescriptions, or medications taken too
frequently or at inappropriate times.
prescribing cascade
an adverse drug reaction
is misinterpreted as a new medical condition, a drug is
prescribed for this condition, another adverse drug effect occurs,
the patient is again treated for the perceived additional
medical condition, and the sequence perpetuates new adverse
events.
Ac
before meal
Pc
After meal
Hs
At bedtime
Qd
Every day
PO
Per oral
Absorption medication affect by
Reduced gastric acid, increased gastric pH, delayed gastric emptying, and the presence of other substances
Age-related physiological changes that affect the action of medications in older adults
Decline in renal function (eGFR) - older adults have slower GFR
Hepatic blood flow declines
Decreases muscle mass and water content
Low serum albumin (protein)
Altered receptor sensitivity
What affects medication-taking behaviour
Motivation
Knowledge abt med
Cultural and psychosocial influences
Physical ability to remove the substance from the container and administer it
Ability to swallow oral preparations
Additional skills related to administering nasally, transdermally, SC and other routes
Considerations of polypharmacy
All meds have side-effects
Older adults are more likely to experience stronger side-effects
Always consider wether the benefit outweighs the risk
Side-effects and medication
Every med has side-effects, they are just not necessarily common
Narcotics do what
Slow respiratory rate
Functional consequences associated with medications in older adults
Disease or polypharmacy may alter the
therapeutic effects of a medication
Adverse effects
Anticholinergic Adverse Effects
Altered mental status
Antipsychotics in people with dementia
Tardive Dyskinesia and Drug-Induced
Parkinsonism
Factors that increase older adults risk for adverse events
Higher number of medications
* Malnourishment or dehydration
* Multiple comorbidities
* An illness that interferes with cardiac, renal or
hepatic function
* Cognitive impairment
* History of medication allergies or adverse effects
* Fever that can alter the action of certain
medications
* Recent change in health
* Certain medications: anticoagulants/
antiplatelets, antidiabetics, NSAIDs, CNS drugs
Antipsychotics should not be given to
Dementia
Anticholinergics
Drugs blocking action of AcH, inhibiting the parasympathetic NS
Higher specificity to older adults (Often not reccomended if better option available)
Morbidity
Illness