Considerations in Geriatric Dosing Flashcards
young old
b/w 65-80
old old
80-85
Given an elderly patient, identify the impact of age on prescribing a medication
Age: plays a role in estimating prognosis or length of life
• How long a person is expected to live is taken into consideration when weighing the risk to benefit assessment therapy.
• Are the potential adverse effects outweighed by the benefits? Will the person live long enough to benefit from the use of the medication?
Given an elderly patient, identify the impact of living environment on prescribing a medication
- Do they live independently? Are they dependent on someone for a place to live? To buy groceries? To prepare their meals? To administer medications? To pay their bills? To bring them to the doctor?
- Do they have control over their environment? Is it safe? Do they have nurse aids or other help that comes into their home?
- How vulnerable are they? In their physical environment? Are they abused by others- financial, physical, emotional?
Given an elderly patient, identify the impact of health and functional status on prescribing a medication
impaired cognitive function may increase the risk of medication non-adherence
• Multiple comorbidities with multiple medications increase the risk of drug-drug and drug-disease interactions.
• Physical or functional deficits could impair the person’s ability to self-manage their disease or limit ability to meet the complexities of a multi-drug treatment regimen
Identify the factors associated with adverse drug effects in the elderly.
number of medications that are used
• Increase number of co-morbidities
• Nonadherence
• Inappropriate drug prescribing
• Functional ability to administer medications correctly
• Cognitive ability to follow instructions, interpret prescription labels and to organize a routine
• Withdrawal events: upon removal of a drug an adverse effect occurs- most commonly with cardiovascular and CNS drugs
• Depression, dementia
• Use of specific drugs for pain, anticholinergic, anticoagulants, and benzodiazepines
• Financial
• When transitioning from one area of care to another
Identify the pharmacokinetic changes in absorption associated with aging
slowing of GI transit time, decreased first pass after oral administration (could result in higher bioavailability), thinner skin, cooler skin temperature, reduced blood flow, lower water content in the elderly
• Drugs given for acute illness can have delayed onset and delayed time to peak effect
• Little data on the effects of aging skin on transdermal absorption
• Heart failure can affect the absorption and bioavailability of some medications
• Overall, minimal clinical significance in the absence of GI pathology in regards to absorption
Identify the pharmacokinetic changes in distribution associated with aging
- Decrease in total body water- water soluble medications will have a smaller volume to distribute into; not reducing the dose increases the risk of ADE or toxicity
- Decrease in lean muscle mass- smaller volume for distribution; not reducing the dose increases the risk of ADE or toxicity
- Increase in body fat mass- patients will not be able to clear fat-soluble medications as quickly leading to ADE or toxicity
- Malnutrition and fragility can lead to a decrease in plasma protein resulting in a decrease in plasma protein binding sites; this change can result in the increase in the percent of unbound or drug free to exert an effect
Identify the pharmacokinetic changes in metabolism associated with aging
- Decrease in size of liver and reduced blood flow occur with aging; drugs with high liver extraction will have a decreased first pass effect, higher systemic bioavailability (patients will be at risk for ADE and toxicity if dose is not lowered)
- Phase 1 metabolism through CYP enzymes probably decrease; impact of these changes in an individual geriatric patient will vary
- Phase 2 metabolism doesn’t appear to be affected
Identify the pharmacokinetic changes in elimination associated with aging
- Renal mass and blood flow are reduced with age
- Creatinine clearance needs to be evaluated and drugs that rely on renal excretion particularly of active drug need to be adjusted
- All drug monographs will indicate whether or not a drug dose needs to be adjusted when renal function is reduced
Define the Beers criteria and its use in avoiding inappropriate medications in the elderly.
Beers criteria: a list of drugs to avoid in the elderly- developed by the American Geriatrics Society (most recent update in 2015)
• Approx. 100 medications and doses considered to be potentially inappropriate for the elderly
• Risk exceeds the benefit
• Safer alternatives available
• Use of medications on this list is associated with decrease quality of life and increased risk of hospitalizations
Identify the reasons for nonadherence in the elderly
- Forgetting to take medication
- Assess for depression
- Number of medications
- Complexity of regimens- simplify regimens and use combination products dosed less frequently
- Assess for adverse drug events
- Financial impact- high co-pays are a real barrier
- Cognitive functionality or decline
Choose interventions that increase medication safety
- Minimize medications and optimize effective non-drug therapy
- Consider Beers list for medication to avoid
- Keep accurate list of all medications (OTC, herbals, dietary supplements, and home remedies)
- Particular attention needs to be paid during health care transitions to ensure orders for medications are reconciled
- Minimize number of health care prescribers
- Encourage use of a single pharmacy
- Communication is very important (between provider and care taker/patient)
- Assess adherence
- Monitor for efficacy and safety
MASTER
o Minimize number of drugs used- use the fewest number of drugs possible
o Alternatives should be considered- evaluate alternative forms of therapy, drug choices, dosage forms
o Start low and go slow
o Titrate therapy- adjust dose according to individual characteristics and readjust dose to optimize response
o Educate- educate patient, caregiver, family regarding the need for and potential problems with therapy
o Review regularly- monitor response regularly and review need periodically
