Question 1

Harry,a 70-year-old,and Ben,a 28-year-old,are taking the same dose of a certain drug that needs to undergo oxidation in their bodies.How will the drug metabolism in Harry's body differ from that in Ben's body?

Accepted Answer

In general, the rate of drug metabolism decreases with age, although there is much variability. The pharmacological effects of drugs requiring oxidation, the benzodiazepines (diazepam, Valium) for example, are usually prolonged with age.

Question 2

Arthur,a 70-year-old,and Kevin,a 24-year-old,are given the same dose of a certain water-soluble drug X.When Dr.Robinson examines samples of their blood plasma,he finds that the concentration of X in Arthur's system is much higher than the concentration of X in Kevin's system.Why is Arthur's blood plasma more concentrated with drug X than Kevin's blood plasma?

Accepted Answer

The percentage of lean body mass (muscle) and the percentage of total body water decrease with age. If one thinks of the body as a big beaker filled with 35 liters of fluid and a drug dose dumped into the beaker, there will be a certain concentration of drug per liter. As the percentage of water decreases, the same dose will produce a higher concentration of drug in the beaker. The same thing occurs in the body. As one becomes older, the same dosage of drug given to a younger adult will produce a higher drug concentration in the elderly.

Question 3

A decrease in renal function is associated with:

Accepted Answer

Age-related decreases in renal function and blood flow slow the rate of drug excretion and increase the duration and intensity of drug action.

Question 4

Which of the following age-related changes is responsible for the decrease in the rate of drug metabolism in elderly patients?

Accepted Answer

The age-related decreases in liver blood flow and production of some drug microsomal metabolizing enzymes (DMMS) reduce the rate of drug metabolism.

Question 5

Equal doses of a certain fat-soluble drug are administered to two individuals,John,who is 20 years old and Eric,who is 70 years old.Which of the following is most likely to happen based on the information provided in this scenario?

Accepted Answer

The drug will have a longer half-life in Eric's body than it will have in John's body. The percentage of body fat increases with age. This causes lipid-soluble drugs to be more widely distributed to the body organs that have a high fat content, such as adipose tissue and muscle, and away from the liver and kidneys. Since the liver and kidneys are responsible for drug metabolism and excretion, any diversion from them will slow elimination of the drug from the body. The drug will then have a longer half-life and duration of action.

Question 6

Ken,a 60-year-old,has been taking daily doses of certain fat-soluble drugs.Identify an accurate statement about how these drugs will get distributed in Ken's body.

Accepted Answer

The percentage of body fat (adipose tissue) increases with age. This causes lipid-soluble drugs to be more widely distributed to the body organs that have a high fat content, such as adipose tissue and muscle (modest fat content, but large mass), and away from the liver and kidneys. Since the liver and kidneys are responsible for drug metabolism and excretion, any diversion from them will slow elimination of the drug from the body.

Question 7

Why do fat-soluble drugs have a longer half-life and duration of action in the elderly?

Accepted Answer

The percentage of body fat increases with age. This causes lipid-soluble drugs to be more widely distributed to the body organs that have a high fat content, such as adipose tissue and muscle, and away from the liver and kidneys. Since the liver and kidneys are responsible for drug metabolism and excretion, any diversion from them will slow elimination of the drug from the body. The drug will then have a longer half-life and duration of action.

Question 8

Which of the following pharmacokinetic processes is most affected by the reduction of renal blood flow with age?

Accepted Answer

The reduction of renal blood flow with age has a significant effect on the renal elimination of drugs. Renal excretion is probably the most important pharmacokinetic process that is affected by age.

Question 9

The drug morphine has a high first-pass metabolism.What change in the dosage of morphine would have to be made if the drug were to be administered to an elderly patient?

Accepted Answer

Drugs that normally undergo first-pass metabolism are not as extensively metabolized during the first pass through the liver. This allows a greater amount of drug to be absorbed, an example of increased bioavailability.

Question 10

Who among the following is most likely to have the lowest rate of drug metabolism?

Accepted Answer

The age-related decreases in liver blood flow and production of some drug microsomal metabolizing enzymes (DMMS) reduce the rate of drug metabolism. Other factors such as smoking, alcohol consumption, and the administration of certain drugs, all of which may cause microsomal enzyme induction, will increase the rate of drug metabolism.

Question 11

Which of the following changes takes place as a person ages?

Accepted Answer

The size of most body organs decreases with age and, therefore, there are fewer cells to carry out organ functions.

Question 12

The enzymes that are most affected by the process of aging are those that play a role in _____ drugs.

Accepted Answer

The age-related decreases in liver blood flow and production of some drug microsomal metabolizing enzymes (DMMS) reduce the rate of drug metabolism. The enzymes that are most affected appear to be the enzymes that oxidize drugs, referred to as the mixed-function oxidase system.

Question 13

In comparison to the members of other age groups,members of the geriatric population are:

Accepted Answer

Drug use increases with increasing age, and the number of drugs consumed in the geriatric population averages between three and four drugs per individual. Both the nature and frequency of adverse drug reactions increase with age.

Question 14

Which of the following may contribute to drug toxicity in the geriatric population?

Accepted Answer

The concentration of plasma proteins, mainly albumin, decreases with age. Since most drugs are bound to some extent to plasma proteins and it is only the concentration of "free drug" that produces the pharmacological effect, any decrease in plasma proteins and plasma protein drug binding will increase the amount of free or unbound drug and, therefore, the intensity of the drug effect.

Question 15

Identify an accurate statement about the use of drugs in the elderly.

Accepted Answer

Compared to other age groups, the geriatric population accounts for the highest percentage of drug prescriptions per year.

Question 16

How would John,an elderly patient who smokes and consumes alcohol,tolerate an adult-strength dose of actively oxidized medication in comparison to Rick,an elderly patient who neither smokes nor drinks?

Accepted Answer

John would be able to metabolize the drug at a faster rate than Rick would be able to metabolize it. Factors such as smoking, alcohol consumption, and the administration of certain drugs may cause microsomal enzyme induction, which will increase the rate of drug metabolism.

Question 17

Drugs are mainly eliminated from the body by _____.

Accepted Answer

Drugs are eliminated from the body mainly by renal excretion and gastrointestinal elimination.

Question 18

An elderly man has been taking an adult-strength dose of the topical steroid hydrocortisone for the past four weeks.He has developed thin skin and stria along his back,which are physical indications of toxicity.Which of the following might have led to the toxic effects of the steroid?

Accepted Answer

The percentage of body fat (adipose tissue) increases with age. This causes lipid-soluble drugs to be more widely distributed to the body organs that have a high fat content, such as adipose tissue and muscle (modest fat content, but large mass), and away from the liver and kidneys.

Question 19

Which of the following changes in aging people tends to slow down the rate of drug absorption and the onset of drug action?

Accepted Answer

With age there is a decrease in blood flow to the intestinal tract, reduced intestinal absorptive surface area, a decrease in gastric acid secretion, and a decrease in intestinal motility. These changes tend to slow the rate of drug absorption and the onset of drug action.

Question 20

Dr.Hampton administers the same dose of a certain water-soluble drug to two of his patients,Nathaniel,who is 65 years of age,and Mark,who is 25 years of age.Which of the following is most likely going to happen?

Accepted Answer

In the bodies of older people, water-soluble drugs will have less body fluid in which to dissolve and are less widely distributed out to the organs with high fat content. This produces higher plasma drug levels and greater pharmacological effects when compared to the same dosage of drug administered to a younger adult.

Quiz 3: Geriatric Pharmacology