Master Drug Movement: ADME in Pharmaceutics for MPharm Students

Question 1

What is the formula for calculating renal clearance, and how can it be used to estimate a drug's elimination rate?

Accepted Answer

Renal Clearance = (Glomerular Filtration Rate (GFR) x Filtration Fraction) + (Tubular Secretion Rate - Tubular Reabsorption Rate)

Answer

Renal Clearance = GFR x Filtration Fraction

Answer

Renal Clearance = Tubular Secretion Rate - Tubular Reabsorption Rate

Answer

Renal Clearance = Elimination Rate / Plasma Concentration

Question 2

Which of the following is NOT a key factor influencing drug absorption through the gastrointestinal tract?

Accepted Answer

Rate of gastric emptying

Answer

Gastric pH

Answer

Presence of food

Answer

Dosage form

Question 3

The process by which a drug is transported from the site of administration to various tissues and organs is known as:

Accepted Answer

Distribution

Answer

Metabolism

Answer

Excretion

Answer

Transport

Question 4

Which organ is primarily responsible for the majority of drug metabolism in the body?

Accepted Answer

Liver

Answer

Heart

Answer

Kidneys

Answer

Lungs

Question 5

The term 'bioavailability' refers to:

Accepted Answer

The fraction of an administered dose that reaches the systemic circulation

Answer

The rate at which a drug is absorbed into the bloodstream

Answer

The duration of action of a drug

Answer

The therapeutic index of a drug

Question 6

The enzyme family responsible for the majority of phase I drug metabolism reactions is:

Accepted Answer

Cytochrome P450

Answer

Alcohol dehydrogenase

Answer

UDP-glucuronosyltransferase

Answer

Epoxide hydrolase

Question 7

Discuss the impact of drug ionization on drug absorption and distribution, emphasizing its significance.

Accepted Answer

Ionized drugs are less readily absorbed than unionized drugs due to their reduced membrane permeability.

Answer

Drug ionization has no significant impact on drug distribution within the body.

Answer

Drug ionization is only relevant in the context of drug excretion and does not affect absorption or distribution.

Answer

Ionized drugs have a higher affinity for plasma proteins compared to unionized drugs.

Question 8

Describe the mechanism of passive diffusion and explain its significance in facilitating drug absorption across biological membranes.

Accepted Answer

Passive diffusion involves the movement of drug molecules across membranes down a concentration gradient, without energy input.

Answer

Passive diffusion occurs against a concentration gradient, requiring active transport of drug molecules across membranes.

Answer

Passive diffusion is only relevant for drugs with high lipid solubility and small molecular weight.

Answer

The physicochemical properties of drugs do not affect the rate of passive diffusion.

Question 9

Which of the following factors does NOT influence drug absorption?

Accepted Answer

Body weight

Answer

Surface area of the absorption site

Answer

Physicochemical properties of the drug

Answer

Molecular size and solubility of the drug

Question 10

The primary mechanism for drug distribution in the body is:

Accepted Answer

Passive diffusion

Answer

Ultrafiltration

Answer

Active transport

Answer

Pinocytosis

Question 11

Which enzyme family is predominantly responsible for drug metabolism?

Accepted Answer

CYP450 enzymes

Answer

Esterases

Answer

Transferases

Answer

Proteases

Question 12

The most common route of drug excretion is:

Accepted Answer

Renal excretion

Answer

Pulmonary excretion

Answer

Biliary excretion

Answer

Integumentary excretion

Question 13

Which of the following factors does NOT significantly influence drug absorption through the gastrointestinal tract?

Accepted Answer

pH of saliva

Answer

Surface area of the small intestine

Answer

pH of gastric contents

Answer

Presence of food in the stomach

Question 14

Which enzyme system is primarily involved in Phase I metabolism of drugs?

Accepted Answer

Cytochrome P450

Answer

Alcohol dehydrogenase

Answer

UDP-glucuronosyltransferase

Answer

Sulfotransferase

Question 15

Which of the following organs is NOT a major route of drug elimination?

Accepted Answer

Brain

Answer

Liver

Answer

Kidney

Answer

Skin

Question 16

What is the process by which a drug molecule moves across a biological membrane from an area of higher concentration to an area of lower concentration?

Accepted Answer

Passive diffusion

Answer

Active transport

Answer

Facilitated diffusion

Answer

Pinocytosis

Question 17

Which of the following factors can lead to an increased volume of distribution for a drug?

Accepted Answer

High protein binding

Answer

Low solubility

Answer

Rapid metabolism

Answer

High urinary excretion

Question 18

What is the primary purpose of Phase II metabolism in drug disposition?

Accepted Answer

To increase drug water solubility

Answer

To activate prodrugs

Answer

To generate toxic metabolites

Answer

To terminate drug action

Question 19

What is the term used to describe the phenomenon where a drug's clearance increases as its dose is increased?

Accepted Answer

Nonlinear kinetics

Answer

Linear kinetics

Answer

Saturation kinetics

Answer

First-order kinetics

Question 20

Which type of drug would be expected to have the largest volume of distribution?

Accepted Answer

Highly lipophilic drug

Answer

Drug that is extensively bound to plasma proteins

Answer

Drug that is rapidly eliminated

Answer

Highly water-soluble drug

Question 21

A drug with a high first-pass metabolism is likely to have a ______ bioavailability compared to a drug with low first-pass metabolism.

Accepted Answer

Lower

Answer

Higher

Answer

Unpredictable

Answer

Similar

Question 22

A drug that undergoes extensive hepatic metabolism is likely to have a ______ half-life compared to a drug that is minimally metabolized in the liver.

Accepted Answer

Shorter

Answer

Variable

Answer

Similar

Answer

Longer

Question 23

Which of the following routes of drug administration bypasses the first-pass effect?

Accepted Answer

Intravenous

Answer

Subcutaneous

Answer

Oral

Answer

Rectal

Question 24

A drug that is primarily excreted unchanged in the urine is likely to have a ______ molecular weight and ______ polarity compared to a drug that undergoes extensive metabolism.

Accepted Answer

Lower, higher

Answer

Higher, higher

Answer

Higher, lower

Answer

Lower, lower

Question 25

Which of the following statements about the blood-brain barrier (BBB) is TRUE?

Accepted Answer

The BBB limits the passage of many drugs into the central nervous system (CNS).

Answer

The BBB is easily permeable to all drugs.

Answer

The BBB is only a factor in the distribution of drugs that target the CNS.

Question 26

A patient with impaired renal function is likely to experience ______ drug accumulation compared to a patient with normal renal function.

Accepted Answer

Increased

Answer

No change in

Answer

Decreased

Answer

Variable

Question 27

Which of the following enzymes is primarily responsible for the metabolism of many drugs in the liver?

Accepted Answer

Cytochrome P450 (CYP450)

Answer

Alcohol dehydrogenase

Answer

Glutathione S-transferase

Answer

Monoamine oxidase

Question 28

A drug that exhibits a high volume of distribution (Vd) is likely to be ______ distributed in the body compared to a drug with a low Vd.

Accepted Answer

More widely

Answer

Equally

Answer

Unpredictably

Answer

Less widely