5.5 Geriatric Kinetics - Zagar

why is it hard to predict PKPD in elderly ppl

lack of control for many variables like age, age comparison, health status, drug therapy, nutritional status, and environment

the _____ of absorption can decrease or is unchanged in elderly pts

rate

the rate of absorption can _____ in elderly pts

decrease or is unchanged

the ____ of absorption is unchanged in elderly ppl

extent

the extent of absorption is ___ in elderly ppl

unchanged

what complications of aging leads to altered absorption of meds?

decreased GI blood floe

decreased gastric acid secretion which increases pH

slower Gi motility and emptying

when gastric acid secretion decreases, it leads to ____ pH and that leads to _______ B12, Fe, and Ca

increased

decreased

when gastric acid secretion decreases, it leads to increased pH and that leads to decreased levels of…

B12, Fe, and Ca

slower GI motility and emptying leads to increased risk of ulceration with which 2 drugs?

ASA and NSAIDs

oral absorption change in elderly

delayed but no change overall

body composition alters which pharmacokinetic property?

distribution

with age, we have decreased lean body mass and total body water, this leads to…

decreased distribution for water soluble drugs

with age, we have decreased lean body mass and total body water, this leads to decreased distribution for water soluble drugs which ultimately leads to…

increased plasma concentrations and higher peaks

as body fat increases, what effect does this have on volume of distribution?

fat soluble drugs will accumulate

leading to prolonged duration of action

what age related changes lead to altered metabolism of drugs?

decreased hepatic mass

decreased hepatic blood flow

decreased hepatic metabolism

when hepatic metabolism declines with age, it leads to _____ bioavailability

increased

bioavailability increases for which three drugs when hepatic metabolism declines with age?

verapamil

propranolol

morphine

what age related issues contribute to altered excretion of meds?

decreased renal mass

decreased renal blood flow

decreased number of functional glomeruli

decreased globular filtration

decreased globular filtration leads to…

accumulation of renally eliminated drugs and metabolites

explain how GFR declines with age

down 1% every year past 20 yo

regular acting insulin may begin to act as a ______ acting insulin with age

long

vitamin D is activated in the _____

kidney

excretion adjustments are estimated on _____

CrCl

what factors help determine CrCl estimates

age, IBW, and SCr

CNS changes with age

smaller reserve of NTs

increased permeability of BBB

increased sensitivity of BZD receptors

increased sensitivity to anticholinergic

as we age, there is a smaller reserve of NTs, this leads to…

inability to compensate for changes easily

as we age, the permeability of the brain _____, this leads to ______ of psychoactive drugs

increases, increases

as we age, the sensitivity of BZD receptors _____ and the sensitivity of anticholinergics ________

increases; increases

in the phrase “start low and go slow”, what does start low address?

changes in distribution and PD

in the phrase “start low and go slow”, what does go slow address?

change in metabolism and excretion

longer intervals for meds addresses changes to ____

PD