Geriatric drugs Flashcards
What is the definition of polypharmacy?
Greater than 5 drugs/week
What are the two leading causes of death in ages over 65?
Heart disease
CA
What is the “prescribing cascade”?
Prescribing a drug, which causes an adverse effect, and prescribing another b/c you interpreted the new symptom is a new problem, rather than a side effect
What are the ways to prevent the prescribing cascade?
- Avoid prescribing until confirm dx
- Titrate slowly
- Add one drug at a time
In is inadequate monitoring?
A medical problem is being treated with the correct dru, but the pt is not monitored for complications, efficacy, or both
What is it called when a medical problem that requires drug therapy is being treated with a less than optimal drug?
Inappropriate drug selection
What is it called when a patient is taking a drug for no medically valid reason?
Inappropriate treatment
What is Beer’s criteria?
List of medications likely to cause adverse effects in the elderly
What are the three criteria that are used in the Beers criteria?
- Drugs problematic is most older pts
- Problematic for certain diseases
- Drugs to be used with caution
What are the three major physiological functions that decline with age, and are relevant to pharmacokinetics?
- Glomerular filtration rate
- Max breathing capacity
- Cardiac index
What happens with weight as we age?
Goes down, but fat mass goes up
What happens to total body water with age?
Decreases
What happens to lean body mass with age?
Decreases
What happens to myocardial sensitivity to beta adrenergic stimulation?
Decreased
What happens to baroreceptor sensitivity with age?
Decrease
What happens to CO with age? TPR?
Lower CO
Increased TPR
What happens to liver size with age? Hepatic blood flow?
both Decrease
What happens to pulmonary function in general with age? Renal function?
Decrease
What are the four components of pharmacokinetics?
Absorption
Distribution
Metabolism
Clearance/elimination
What is the parameter of drug pharmacokinetics that is least affected by aging?
Absorption
Why is first pass metabolism reduced with aging?
Reduced liver function and blood flow
What is bioavailability?
Fraction of drug reaching the systemic circulation (IV dose = 100%)
What is the relative dose needed for a prodrug in the elderly? Why?
Increased dose d/t lower metabolism by the liver
What is the equation for the volume of a drug’s distribution?
Amount of drug in body (mg) / plasma [drug]
A large Vd indicates what?
Most of the drug is in the extravascular compartment