Lecture 8 - Geriatric Pharmacology Flashcards
why study geriatrics as a unique population?
geriatric patients have far more toxicity than any other age groups, they take multiple medications at once, etc.
list the nine factors which make geriatrics a unique speciality
- changes associated with primary aging
- secondary aging (disease)
- multimorbidity
- geriatric syndromes (ex: falls)
- multiple medications
- setting of care
- policy decisions (drug coverage, cost, access)
- psychosocial issues (widowhood, isolation, poverty)
- ethics and advocacy (paternalism)
what is the age range for the “young old” category?
65-74
what is the age range for the “middle old” category?
75-84
what is the age range for the “old old” category?
85+
someone who has lived to be 100 years
centenarian
someone who has lived to be 110 years
super centenarian
someone aged 105-109 years
semi-super centenarian
why are older adults broken down into smaller age categories?
to minimize the differences in abilities and functions
in 2016, the number of seniors living in Canada surpassed:
the number of children living in Canada
what percent of the population was made of senior citizens in July 2022?
18.8%
what percent of seniors have at least one chronic condition?
76%
the prescence of two or more long-term health conditions
multimorbidity
why does multimorbidity present a challenge in drug trials?
we study drugs in single conditions, not multiple conditions at once
multimorbitity is associated with ____ and ____
age, number of medications (linear)
a state of increased vulnerability from age-associated decline in reserve and function resulting in reduced ability to cope with everyday or acute stressors
frailty
a gradual decrease in physiological reserve occurs with aging. in frailty, this decrease is:
accelerated and homeostatic mechanisms start to fail
on the clinical frailty scale: people who are robust, active, energetic, and motivated. these people commonly exercise regularly.
1) very fit
on the clinical frailty scale: people who have no active disease symptoms, and exercise somewhat often.
2) well
on the clinical frailty scale: people whose medical problems are well controlled, but are not regularly active beyond reoutine walking
3) managing well
on the clinical frailty scale: people who are not dependent on others for daily help, but often symptoms limit activities
4) vulnerable
on the clinical frailty scale: these people often have more evident slowing, and need help in high orders tasks (ex: finances, housework).
5) mildly frail
on the clinical frailty scale: people need help with all outside activities and with keeping house. inside, they often have problems with stairs and need help with bathing, and might need minimal assistance with dressing
6) moderately frail
on the clinical frailty scale: people are completely dependent for personal care, from whatever cause (physical or cognitive). even so, they seem stable and not at high risk of dying
7) severely frail
on the clinical frailty scale: people who are completely dependent, approaching th end of life. typically, they could not recover even from a minor illness
8) very severely frail
on the clinical frailty scale: people who are approaching the end of life (life expectancy of <6 months)
9) terminally ill
a multifactorial condition that involves the interaction between identifiable situation-specific stressors and underlying age-related factors, resulting in damage across multiple organ systems
geriatric syndrome
what are the four key features of geriatric syndrome?
- clinical and multifactorial conditions in older persons
- associated with poor health outcomes
- do not fit into disease categories (co-morbidities)
- require a multidimensional treatment approach
go review slide 216 of your notes
you’re doing great!
what is pharmacoepidemiology?
a multifaceted discipline that combines the principles of both pharmacology and epidemiology for the study of the use and effects of drugs in extensive populations
a medication or medication class where harm outweighs the benefit, and there are safer alternatives available
potentially inappropriate medications
the Beers criteria is used by the Canadian Institute of Health Information (CIHI) and American Geriatrics Society (AGS) to identify:
potentially inappropriate medications (PIMs)
what is the goal of the WHO Global Patient Safety Challenge?
the reduce severe, avoidable medication-related harm by 50% over the course of 5 years
how much money does medication errors cost?
$42 billion USD
what are the priority actions of the WHO Global Patient Safety Challenge?
- managing high risk situations (including children and older adults)
- polypharmacy
- transitions in care
which groups are at the highest risk of experiencing an adverse drug reaction (ADR)?
1) people with multiple chronic conditions
2) women
3) people over the age of 65
what is polypharmacy?
literally, taking 2 or more medications; but practically, taking 5 or more medications
the use of one drug to treat the adverse effects of another
drug cascades (polypharmacy)
not prescribing medications to patients who would benefit from it
potential prescribing omissions (PPO)
PPO is often seen in patients with:
polypharmacy
recent studies of hospitalized patients show ____% admitted had a PPO per the ____
83%, START criteria
what is the START criteria?
says: that’s a potentially appropriate medication that you should continue on or start
true or false: aging is synonymous with disease
false
each organ system has changes associated with aging, which often starts in the:
fifth decade
what are five implications of physiologic aging?
- reduced tissue/organ function
- functional decline
- increased susceptibility to disease
- change in behaviour
- differences in pharmacokinetics and pharmacodynamics
how does body composition change with age?
loss of muscle mass, function and quality of muscle changes, fat mass increases
how does the cardiovascular system change with age?
decreased cardiac output, decreased beta sensitivity
how does the renal system change with age?
decreased glomerular filtration rate, decreased nephrons
how does the gastrointestinal system change with age?
decreased H+, increased gastric emptying time
how does the hepatic system change with age?
decreased size, decreased blood flow
how does the nervous system change with age?
decreased blood flow to the CNS
how does the pulmonary system change with age?
decreased cilia
how does the endocrine system change with age?
decreased hormonal secretions
how does gastrointestinal absorption change with aging?
- potential for delay in absorption
- active transport may be reduced
how does intramuscular/topical absorption change with aging?
- slower, erratic, or lower absorption
- higher absorption of topical steroids
most drugs are _____ in older adults
well absorbed
drug absorption can be affected by:
other conditions or medications
what is the affect on Vd as body water levels decrease with age?
decreased Vd for hydrophilic drugs
what is the affect on Vd as lean mass decreases with age?
decreased Vd for drugs that bind to muscle, or are water soluble
what is the affect on Vd as fat stores increase with age?
increased Vd for lipophilic drugs
what is the affect on Vd as albumin levels decrease with age?
increased percent of unbound or free drug
protein changes with aging are:
insignificant and rarely have an impact on drug therapy
protein changes often occur with:
concurrent illness, not aging
what physiological changes impact drug metabolism?
decreased hepatic mass, hepatic blood flow, and CYP P450 content
what are the pharmacokinetic effects of altered metabolism associated with age?
decreased first pass metabolism, phase I metabolism, and phase II metabolism (if frail older adult)
what is the effect of reduced phase I metabolism?
slower/lower conversion to metabolites
phase II metabolism is largely _____ in older adults, with the exception of _____
in tact, frail older adults
drugs metabolized by _____ are preffered in older adults
phase II metabolism
for medications that are oxidatively metabolized, the dose must be ______ for older adults
reduced
multiple medications can have a more dramatic drug interaction if impacting the:
CYP P450 enzyme system
metabolism of drugs can be dramatically affected by _____ in older adults
illness (particularly acute illness)
other factors which affect drug metabolism include:
chronic illness, genetics, diet, smoking, and ethanol use
what physiological changes impact drug elimination?
decreased renal blood flow, glomerular filtration rate, and tubular secretion
what are the pharmacokinetic effects of altered elimination associated with age?
renally eliminated drugs are delayed, and there is a longer half-life of renally eliminated drugs
what is the single most clinically significant change in pharmacokinetics due to aging?
decreased renal elimination of drugs
the majority of drug dosage adjustments in older adults are due to:
renal function
what are the pharmacodynamic changes associated with aging?
- changes in homeostatic regulation
- change in receptor responsiveness
- increased sensitivity to drugs
what are the changes in receptor responsiveness associated with aging?
- change in receptor density
- change in receptor affinity
- post-receptor changes
- change in negative feedback
what is the paradox of drug exposure?
in most cases there is increased sensitivity, but we would expect decreased sensitivity
increased drug sensitivity leads to:
increased risk of an adverse drug event (ADE)
