geriatrics

Question 1

what are some physiological changes associated with the kidney in geriatric patients?

Answer 1

-decreased renal blood flow
-decreased renal mass
-decreased GFR
-decreased renal tubular secretion and reabsorption
-decreased ability to excrete a free-water load

Question 2

what are some physiological changes associated with the liver in geriatric patients?

Answer 2

-decreased hepatic mass
-decreased hepatic blood flow
-decreased activity of P-450 enzyme system

Question 3

skin is our largest organ with vital functions, may be compromised by age related changes such as:

Answer 3

-skin is drier, thinner (barrier function loss therefore increased risk of infection)
-prolonged healing time after injury
-changes in skin appearance

Question 4

do the elderly have a higher or lower pH in GI tract?

Answer 4

higher - due to antacids, PPI’s etc

Question 5

do the elderly have a delayed or faster stomach emptying time?

Answer 5

delayed

Question 6

what factors affect drug absorption in the elderly?

Answer 6

-higher pH in GI tract
-delayed emptying time
-diarrhea/gastroenteritis
-feedings (enteral feeds, liquid supplements)
-less muscle tone
-thinner and dryer skin

Question 7

which type of drugs have a higher absorption in the elderly that have a higher GI pH and which drugs have decreased absorption?

Answer 7

increased absorption of basic and acid-labile drugs
decreased absorption of acidic drugs

Question 8

how does delayed stomach emptying time affect drug absorption

Answer 8

decreases the amount of drug absorbed and delays the rate of absorption since most drugs are absorbed in the small intestine

Question 9

how do diarrhea and gastroenteritis affect drug absorption

Answer 9

decreased intestinal transit time thus less absorption

Question 10

how does constipation affect drug absorption?

Answer 10

increased intestinal transit time thus more absorption

Question 11

how do feeds such as milk and enteral feeds affect drug absorption?

Answer 11

potenital for drug interacitons

Question 12

how do less bile salts affect drug absorption?

Answer 12

may decrease absorption of fat soluble drugs and vitamins (e.g. via D)

Question 13

what class of drugs may interact with ions?

Answer 13

tetracycline with Fe2+

Question 14

what class of drugs may interact with oils?

Answer 14

highly lipid-soluble drugs may interact with mineral oil

Question 15

what class of drugs may interact with antacids

Answer 15

tetracyclines and ciprofloxacin with antacids

Question 16

what drug may interact with cholestyramine

Answer 16

lovastatin

Question 17

what class of drug may interact with milk/formula

Answer 17

tetracycline

Question 18

do the elderly have an increased or decreased first pass effect?

Answer 18

reduced - elderly have reduced hepatic metabolizing enzymes thus reduced first pass effect.

Question 19

what are the consequences of having a reduced first pass effect in the elderly?

Answer 19

-greater fraction of drug given orally enters into systemic circulation
-potential for increased drug toxicity

Question 20

how does decreased muscle tone have an effect on drug absorption?

Answer 20

-less muscle contractions in elderly
-less muscle oxygenation thus slower drug absorption and less drug absorbed

Question 21

this affects the drug metabolsim

Answer 21

liver

Question 22

this affects the drug elimination from the body

Answer 22

kidneys

Question 23

this affects volume distribution

Answer 23

body composition changes - body ratios of water:muscle:fat are different for newborns, children, adult and the elderly therefore may affect drug disposition depending on chemical composition of the drug (water soluble vs fat soluble)

Question 24

what factors affect drug distribution in the distribution in the elderly

Answer 24

-less total body water content
-less muscle mass
-more body fat
-less plasma protein binding (decreased serum albumin binding); hypoalbuminemia can be due to malnourishment or renal failure

Question 25

is there an increased or decreased vd for water soluble drugs?

Answer 25

decreased - higher drug concentrations (may need to reduce dose)

Question 26

is there an increased or decreased vd for fat soluble drugs?

Answer 26

increased - prolonged drug effects, lower serum drug effects (but elderly may be more sensitive to drug effects), may be at increased risk of toxicity if lose weight and given dose at the same time

Question 27

what happens with plasma protein binding when a patient has hypoalbimunemia

Answer 27

less albumin is present to bind to the drug