Pharmacokinetics: Master Drug Movement in the Body for Pharmacy

Question 1

In the context of drug metabolism, which enzyme is responsible for phase I reactions?

Accepted Answer

Cytochrome P450 (CYP450)

Answer

Uridine diphosphate glucuronosyltransferase (UDP-GT)

Answer

Glutathione-S-transferase (GST)

Answer

Sulfotransferase

Question 2

The clearance of a drug refers to:

Accepted Answer

The rate at which the drug is eliminated from the body

Answer

The steady-state concentration of the drug in the body

Answer

The volume of distribution of the drug

Answer

The duration of action of the drug

Question 3

Which pharmacokinetic parameter is **not** considered when designing optimal drug dosage regimens?

Accepted Answer

Apparent volume of distribution

Answer

Half-life

Answer

Clearance

Answer

Volume of distribution

Question 4

For maximum drug absorption, administer the drug:

Accepted Answer

Dissolved in a liquid

Answer

In solid form

Answer

With a meal

Answer

Subcutaneously

Question 5

The area under the drug concentration-time curve (AUC) represents:

Accepted Answer

The total drug exposure

Answer

The rate of drug absorption

Answer

The extent of drug distribution

Answer

The duration of drug elimination

Question 6

Intravenous administration of drugs offers:

Accepted Answer

Rapid absorption and high bioavailability

Answer

Gradual absorption and low bioavailability

Answer

High first-pass effect and reduced bioavailability

Answer

Inconsistent absorption and variable bioavailability

Question 7

The elimination half-life of a drug indicates the time required for:

Accepted Answer

50% of the drug to be eliminated

Answer

The body to double its clearance

Answer

The volume of distribution to decrease by half

Answer

The drug to be completely absorbed

Question 8

Which route of administration results in the highest bioavailability?

Accepted Answer

Intravenous

Answer

Oral

Answer

Intramuscular

Answer

Subcutaneous

Question 9

The volume of distribution (Vd) is a measure of:

Accepted Answer

The extent to which a drug is distributed throughout the body

Answer

The total amount of drug in the body

Answer

The concentration of drug in the plasma

Answer

The rate at which a drug is eliminated from the body

Question 10

Which of the following enzymes is involved in phase I drug metabolism?

Accepted Answer

Cytochrome P450

Answer

UDP-glucuronosyltransferases

Answer

Sulfotransferases

Answer

Glutathione S-transferases

Question 11

Which organ is primarily responsible for drug excretion?

Accepted Answer

Kidneys

Answer

Liver

Answer

Lungs

Answer

Skin

Question 12

The elimination half-life (t1/2) of a drug represents the time it takes for the:

Accepted Answer

Drug concentration in the body to decrease by half

Answer

Drug concentration in the body to increase by half

Answer

Body to completely eliminate the drug

Answer

Drug to reach its maximum concentration in the body

Question 13

Which of the following is a non-linear pharmacokinetic process?

Accepted Answer

Metabolism

Answer

Absorption

Answer

Distribution

Answer

Excretion

Question 14

Which factor has the least impact on drug absorption?

Accepted Answer

Patient's age

Answer

Physicochemical properties of the drug

Answer

Route of administration

Answer

pH of the gastrointestinal tract

Question 15

Which of the following **is not** a primary determinant of drug distribution in the body?

Accepted Answer

Blood pH

Answer

Protein binding

Answer

Tissue perfusion

Answer

Drug ionization

Question 16

The volume of distribution of a drug is a measure of its:

Accepted Answer

Distribution throughout the body's compartments

Answer

Extent of drug metabolism

Answer

Amount of drug bound to plasma proteins

Answer

Rate of drug elimination

Question 17

Which enzyme system is primarily responsible for phase I drug metabolism?

Accepted Answer

Cytochrome P450

Answer

Acetylcholinesterase

Answer

Lactate dehydrogenase

Answer

Carbonic anhydrase

Question 18

The primary route of elimination for water-soluble drugs is:

Accepted Answer

Glomerular filtration

Answer

Tubular secretion

Answer

Biliary excretion

Question 19

Which of the following factors is MOST LIKELY to increase the risk of drug toxicity in elderly patients?

Accepted Answer

Reduced hepatic function

Answer

Higher body weight

Answer

Increased cardiac output

Answer

Improved renal function

Question 20

A patient is taking a drug with a narrow therapeutic index. Which of the following is a potential consequence of high variability in the patient's drug metabolism?

Accepted Answer

Increased risk of both therapeutic failure and toxicity

Answer

Prolonged duration of action

Answer

Decreased efficacy of the drug

Question 21

Which of the following factors can significantly influence drug absorption from the gastrointestinal tract?

Accepted Answer

Gastric pH, presence of food, and gastrointestinal motility

Answer

Route of administration and drug formulation

Answer

Ambient temperature and humidity

Answer

Patient's age and gender

Question 22

The apparent volume of distribution (Vd) primarily reflects:

Accepted Answer

The theoretical volume of fluid in which a drug appears to be distributed

Answer

The amount of drug bound to plasma proteins

Answer

The rate of drug elimination

Answer

The drug's affinity for specific tissues

Question 23

Which of the following enzymes plays a DOMINANT role in drug metabolism within the liver?

Accepted Answer

Cytochrome P450

Answer

Esterases

Answer

Acetylcholinesterase

Answer

Monoamine oxidase

Question 24

The half-life of a drug is defined as the time it takes for:

Accepted Answer

The plasma concentration of the drug to decrease by 50%

Answer

The drug to be completely eliminated from the body

Answer

The drug to reach its steady-state concentration

Answer

The drug's effect to reach its maximum

Question 25

Which of the following routes of drug administration generally provides the FASTEST onset of action?

Accepted Answer

Intravenous

Answer

Oral

Answer

Rectal

Answer

Transdermal

Question 26

Which of the following conditions is MOST LIKELY to alter drug pharmacokinetics in the elderly?

Accepted Answer

Decreased hepatic blood flow

Answer

Increased muscle mass

Answer

Improved renal function

Answer

Increased gastric pH

Question 27

The therapeutic index of a drug is calculated as the ratio of:

Accepted Answer

Toxic dose to effective dose

Answer

Effective dose to minimum inhibitory concentration

Answer

Maximum tolerated dose to minimum effective dose

Answer

Peak plasma concentration to trough plasma concentration