Ch 11: Drug Therapy in Geriatric Patients Flashcards
What are the 4 reasons geriatric patients experience more adverse drug reactions and drug-drug interactions?
- altered pharmacokinetics (secondary to organ degeneration)
- multiple and severe illnesses
- multidrug therapy
- poor adherence
(p. 92)
Pharmacokinetic changes may be minimal in patients who…
…have remained physically fit.
p. 92
Why might the RATE of absorption (of PO meds) be slowed in geriatric patients?
Because of delayed gastric emptying and reduced splanchnic blood flow.
(p. 92)
What 4 major factors can alter drug distribution in older adults?
- increased percent body fat
- decreased percent lean body mass
- decreased total body water
- reduced concentration of serum albumin
(p. 92)
Why are water soluble drugs in geriatric patients distributed in a smaller volume than in younger adults?
Because of the decline in lean body mass and total body water.
(p. 92)
Why do plasma levels of lipid soluble drugs tend to be reduced in older adults?
Because the increase in body fat seen in older adults provides a storage depot for lipid soluble drugs.
(p. 92)
Why does hepatic drug metabolism decline with age?
Reduced hepatic blood flow, reduced liver mass, and decreased activity of some hepatic enzymes.
(p. 92)
What is the most important cause of adverse drug reactions in older adults?
drug accumulation secondary to reduced renal excretion
p. 92
In older adults, what is the proper index of renal function? Why?
Creatinine clearance, not serum creatinine levels
The source of serum creatinine – lean muscle mass – declines in parallel with the decline in kidney function, which means creatinine levels may be normal even though renal function is greatly reduced.
(p. 93)
Adverse drug reactions are _ times more common in older adults than in younger adults.
7
p. 93
What is the Beers list?
List of drugs with a high likelihood of causing adverse effects in older adults.
(p. 93)
