Question 1

Some active drugs are known to be enzymatically metabolized active metabolites but are not considered prodrugs.Which of the following explains the difference between these drugs and prodrugs?&#10;A)Prodrugs are metabolized into extremely concentrated drugs that reach their steady state in a shorter period of time.&#10;B)Prodrugs do not require enzymatic metabolism to be converted to active metabolites.&#10;C)Prodrugs are not eliminated until they are converted to active metabolites.&#10;D)The active form of a prodrug is either unstable, not readily soluble, or poorly absorbed.

Accepted Answer

The use of prodrugs depends on knowledge of metabolic pathways that will convert the prodrug, which is inactive in administered form, into its active form once in the body.The rationale for the use of prodrugs is that the active form of the prodrug is either unstable (such as in the acidic environment of the stomach), not readily soluble, or poorly absorbed.Thus prodrugs are designed to mask the problem with the active form of the drug long enough to get the drug in the body where it is metabolized into its active form.

Question 2

Kinetic processes related to the fate of a drug in the body, where the drug concentration exceeds the capacity of the system, is known as:&#10;A)zero-order kinetics&#10;B)first-order kinetics&#10;C)Michaelis-Menten kinetics&#10;D)compartmental kinetics

Accepted Answer

Whenever the drug concentration present in a system exceeds the capacity of the system, the rate of change of drug concentration is most precisely described by Michaelis-Menton kinetics.

Question 3

Blood samples should be collected for therapeutic drug monitoring:&#10;A)at the end of the dosing interval (trough level) immediately before the next dose is administered&#10;B)1 to 2 hours after drug administration&#10;C)immediately after drug administration&#10;D)at varied times and based on the characteristics of the particular drug, route of administration, and intent of the drug

Accepted Answer

Blood collection for therapeutic drug monitoring varies depending upon many factors.When a drug is administered intravenously, blood samples are usually collected after distribution, usually 1 to 2 hours after administration.For long-term therapy, blood samples are usually taken after the steady state has been attained; during the steady state, peak or trough samples may be collected, depending upon the clinical question.For some drugs such as phenytoin, timing of the blood sample is not critical because fluctuations between the peak and trough levels are relatively small.With other drugs that have a narrow therapeutic range (e.g., theophylline), it may be necessary to obtain blood samples at peak and trough times.

Question 4

Which of the following statements are true regarding drug half-life?&#10;A)Doubling the dose of a drug will reduce the half-life by one half.&#10;B)Half-life is equal to the time required to change the drug blood level by 50%.&#10;C)Doubling the dose of a drug will double the half-life.&#10;D)both b and c

Accepted Answer

The half-life of a drug is equal to the time required to change the blood level of a drug by 50%.The half-life of a drug is not influenced by the dose.

Question 5

A situation where the amount of drug excreted between two doses is equal to the previous dose administered is known as:&#10;A)a steady-state&#10;B)a half-life&#10;C)maintenance dosing&#10;D)therapeutic drug monitoring

Accepted Answer

Steady-state is achieved when the amount of drug administered equals the amount of drug cleared from the body between doses.

Question 6

In general consideration of drug blood level and the time a drug spends in the body before elimination under normal physiological conditions, which of the statements below is true following a single dose of a drug?

A)The more rapidly the peak concentration is attained, the longer the period of time the drug will spend in the body.
B)The more rapidly the peak concentration is attained, the higher the peak concentration.
C)The more rapidly the peak concentration is attained, the longer the duration at the peak concentration.
D)The longer it takes for the drug to reach its peak concentration, the shorter the period of time the drug will spend in the body.

Accepted Answer

In general terms, following the administration of a single dose of drug, the more rapidly a drug reaches its peak concentration in the blood stream, the higher the peak concentration will be.In addition, the more rapidly a drug reaches its peak concentration, the shorter the duration of time the drug will spend at that peak concentration and the shorter the duration of time the drug will spend in the body.The longer it takes a drug to reach peak concentration, the lower the peak concentration will be.However, for these drugs, the duration of time the drug spends at its peak concentration will be longer, and the duration of time the drug spends in the body will be longer.

Question 7

Kinetic processes related to the fate of a drug in the body, where the rate of change of drug concentration is dependent upon the drug concentration, is known as:&#10;A)zero-order kinetics&#10;B)first-order kinetics&#10;C)Michaelis-Menten kinetics&#10;D)compartmental kinetics

Accepted Answer

First-order kinetics means the rate of change of drug concentration is dependent upon one factor: the concentration of drug present.In this situation, drug is said to be eliminated in a manner that can be described by first-order kinetics.In first-order kinetics, a constant proportion of drug is eliminated per unit time.

Question 8

Kinetic processes related to the fate of a drug in the body, where the rate of change of drug concentration is independent of the concentration of a particular drug, is known as:&#10;A)zero-order kinetics&#10;B)first-order kinetics&#10;C)Michaelis-Menten kinetics&#10;D)compartmental kinetics

Accepted Answer

Zero-order kinetics means that the rate of change of drug concentration is independent of the concentration of the particular drug.In this case, a constant amount of drug is eliminated per unit time.

Question 9

The primary driving force for drugs to move from the point of absorption to the site of action is ______, and the primary driving force for drugs to leave the site of action following a single dose is ______.

A)active transport, active transport
B)active transport, passive transport
C)passive transport, active transport
D)passive transport, passive transport

Accepted Answer

Passive diffusion is the mechanism by which 95% of the drugs move through the body, both to the site of action and away from the site of action.Passive diffusion is based on concentration gradients across membranes.For example, when a drug is administered and enters the blood stream, the drug's concentration in the blood stream is much higher than it is in extravascular fluids.Therefore, the drug will begin to diffuse out of the blood stream into extravascular fluids and then to the site of drug action.Likewise, as the drug is diffusing toward the site of action, it is also diffusing into other compartments in the body or being eliminated from the body.Thus a point will be reached following a single dose where the drug is in greatest concentration at the site of action.Therefore, it will begin its diffusion from the site of action into extravascular fluids and then into the blood stream.At this time, the drug concentration at the site of action will decrease to a point where the action of the drug will no longer occur.

Question 10

Which of the following are considered goals of metabolism?
1)to make the drug more water soluble
2)to make the drug less active
3)to prepare the drug for greater distribution into adipose tissue
4)to increase the half-life of the drug

A)1, 2, 3
B)1, 3, 4
C)1, 2
D)3, 4

Accepted Answer

The goal of metabolism is to convert the drug into a more water-soluble metabolite to prepare the drug for excretion.As the water solubility increases, the lipid solubility decreases.A decrease in lipid solubility makes it more difficult for the metabolite to make its way through cell membranes and so forth to reach the receptor site.As a result, the drug becomes less active than the parent compound.It is important to understand that even though the goal of metabolism is to make the drug less active in the body and to prepare the drug for excretion; this is not always the result of metabolism.

Question 11

Where will an acidic drug with a pK&#8336; of 3.5 have the greatest chance for absorption by passive diffusion?&#10;A)the stomach&#10;B)the skin&#10;C)the intestine&#10;D)the rectum

Accepted Answer

The answer of Where will an acidic drug with a...

Question 12

Considering the administration of a single dose of a hypothetical drug by different routes, which of the following gives the correct order of attaining peak concentration of the drug in the blood stream?

A)intramuscular, oral, intravenous
B)oral, intravenous, intramuscular
C)intravenous, intramuscular, oral
D)intramuscular, intravenous, oral

Accepted Answer

The answer of Considering the administration of a single dose...

Question 13

Given that a drug has a half-life of 10 hours and is administered at a dosing interval of slightly less than the half-life, approximately how long will it take to reach the steady-state level?&#10;A)5 hours&#10;B)10 hours&#10;C)40 hours&#10;D)100 hours

Accepted Answer

The answer of Given that a drug has a half-life...

Question 14

Suppose a patient has been taking a medication for a significant period of time with good results.Recently the patient has begun experiencing toxic side effects after dose administration that subside approximately an hour later.The blood sample that should be collected for an initial evaluation is ______.When this blood level is found to have a drug concentration higher than desired, a laboratory test to evaluate ______ would be advised.

A)trough blood sample, liver function
B)peak blood sample, kidney function
C)trough blood sample, gastrointestinal function
D)peak blood sample, cardiac function

Accepted Answer

The answer of Suppose a patient has been taking a...

Question 15

The two main organs associated with the elimination of drugs are the kidney and the liver.What would be the effect on the blood level-time curve following the administration of a single dose of a medication in the presence of liver disease or renal failure?

A)The peak concentration will decrease, and the duration of time the drug spends in the body will increase.
B)The peak concentration will increase, and the duration of time the drug spends in the body will decrease.
C)The peak concentration will increase, and the duration of time the drug spends in the body will increase.
D)The peak concentration will decrease, and the duration of time the drug spends in the body will decrease.

Accepted Answer

The answer of The two main organs associated with the...

Question 16

It is of particular importance to monitor drug levels in patients for drugs that have a ______ therapeutic index.A therapeutic index of 2.0 is associated with a high likelihood of the patient experiencing ______.

A)low, significant toxicity from the drug
B)low, no toxicity from the drug
C)high, significant toxicity from the drug
D)high, no toxicity from the drug

Accepted Answer

The answer of It is of particular importance to monitor...

Question 17

Different formulations of drugs from different manufacturers may influence the blood level-time curves following the administration of a single dose of medication.If all of the drug is eventually released from the different formulations, which of the following statements describes the correlation between these different formulations?

A)The time the drug spends in the body will be the same for all formulations.
B)The peak concentration will be the same for all formulations.
C)The duration of the peak concentration will be the same for all formulations.
D)The area under the blood level-time curve for each formulation will be the same.

Accepted Answer

The answer of Different formulations of drugs from different manufacturers...

Deck 14: Therapeutic Drug Monitoring