Geriatric Pharmacology Flashcards
Polypharmacy
multiple medications (usually 5-10)
Pharmacokinetics
What the body does to the drug
- Absorption
- Distribution
- Metabolism
- Excretion
Pharmacodynamics
What the drug does to the body
Geriatric and topical route absorption
- thin epidermis
- less subcutaneous fat
=increased topical absorption
Distribution
less body water –> higher serum level for hydrophilic drugs
more fat –> higher volume of distribution for lipophilic drugs (prolonged half life)
Less albumin in plasma –> more active, unbound drug
Which phase of metabolism is most affected in the elderly?
Phase I (decreased metabolism)
ex. CYP450 3A4
Geriatric pharmacokinetics: excretion
- GFR is reduced
- Decreased clearance
What is digoxin dose based on?
- lean body mass
- renal function
What percent of ADEs in elderly are avoidable?
25%
Name the drugs most commonly involved in ADEs
- Cardiovascular drugs
- Diuretics
- NSAIDs
- Hypoglycemics
- Anticoagulants
Name some predictors of ADEs
- 6+ chronic conditions
- 9 or more meds
- Low body weight or low BMI
- 85 years or older
- GFR below 50mL/min (stage 3 and lower)
What is the name for when a drug is prescribed to manage a side effect from another drug?
prescribeing cascade (bad!)
What interaction is there between ACE/ARB and Septra?
hyperkalemia
What interaction is between digoxin and macrolides?
digoxin toxicity
What interaction is between Phenytoin and Septra?
Phenytoin toxicity
What can benzodiazepines, TCA, antipsychotics put a patient at risk for?
Falls/fractures
What can TCAs do to a patient with BPH?
Urinary frequency
What risk is there from putting a heart patient or HTN patient on NSAIDs?
NSAIDs can increase fluid retention and overwork the heart
NSAIDs can also cause bleeding, ulcers
Non adherence may be as high as ____%
50%
What percent of older patients take OTC medication?
72%
Name 5 drugs you should always be considering to discontinue
- Bisphosphonatews
- PPIs
- Iron supplements
- Antipsychotics
- Antidepressants
