MBPL3621 Introduction to Pharmacology Quiz 1 | MCQ Quiz | OmpathStudy Kenya

Question 1

Which process involves the transfer of a drug from its site of administration to the blood stream? Choices:

Accepted Answer

Absorption — Absorption is the movement of a drug from its site of administration into the bloodstream. This process is essential for the drug to reach systemic circulation and eventually its site of action. ---

Question 2

Receptor agonists result in a drug response. Choices:

Accepted Answer

True — Receptor agonists bind to receptors and activate them, producing a biological response. This is the mechanism by which many drugs exert their therapeutic effects. ---

Question 3

Glomerular filtration of a drug is affected by its: Choices:

Accepted Answer

Plasma protein binding — Only free (unbound) drug molecules can be filtered through the glomerulus. Drugs bound to plasma proteins are too large to pass through the glomerular membrane, so plasma protein binding directly affects glomerular filtration. ---

Question 4

For the calculation of the volume of distribution (Vd) one must take into account: Choices:

Accepted Answer

Concentration of a substance in plasma — Volume of distribution (Vd) is calculated using the formula: Vd = Dose / Plasma concentration. It represents the theoretical volume needed to contain the total amount of drug at the same concentration as in plasma. ---

Question 5

This illustration below is concerned with which factor that influences the response to drug therapy. Choices:

Accepted Answer

Rate of metabolism and excretion — The illustration focuses on pharmacokinetics (how the body processes the drug), not pharmacodynamics (drug effects). Metabolism and excretion are pharmacokinetic processes that determine drug concentration over time. ---

Question 6

Increasing the dose of the drug will increase the strength of the bond the drug has with its receptor. As a result, the response will increase. Choices:

Accepted Answer

False — Increasing the dose does not change the strength of drug-receptor binding (affinity). Instead, it increases the number of receptors occupied, which may increase the response up to a maximum effect (efficacy). ---

Question 7

The strength of the drug is related to the dose of the drug. Choices:

Accepted Answer

True — Strength refers to the amount of drug in a dosage form (e.g., 500 mg tablet). Higher doses contain more drug and therefore have greater strength, though this is different from potency, which is a comparative measure. ---

Question 8

What does "pharmacokinetics" include? Choices:

Accepted Answer

Drug biotransformation in the organism — Pharmacokinetics describes what the body does to the drug, including absorption, distribution, metabolism (biotransformation), and excretion (ADME). ---

Question 9

Drugs which undergo high degree of first-pass metabolism in liver: Choices:

Accepted Answer

Have low oral bioavailability — First-pass metabolism occurs when orally administered drugs are metabolized in the liver before reaching systemic circulation, reducing the amount of active drug available and thus decreasing oral bioavailability. ---

Question 10

Bioavailability of drug refers to: Choices:

Accepted Answer

None of the choices — Bioavailability is the percentage of administered dose that reaches systemic circulation in the UNCHANGED (active) form, not "changed form" as stated in option E. None of the provided options correctly defines bioavailability. ---

Question 11

Receptor antagonists result in a drug response. Choices:

Accepted Answer

False — Receptor antagonists bind to receptors but do not activate them. They block the receptor and prevent agonists from binding, thereby inhibiting a response rather than producing one. ---

Question 12

Which of the following are sources for making drugs? Choices:

Accepted Answer

All the choices — Drugs can be derived from multiple sources including animals (e.g., insulin), plants (e.g., morphine), and synthetic/chemical synthesis (e.g., aspirin). Modern pharmaceuticals use all these sources. ---

Question 13

Which process affects bioavailability? Choices:

Accepted Answer

Absorption — Bioavailability is primarily determined by absorption and first-pass metabolism. The extent and rate of absorption directly affect how much drug reaches systemic circulation. ---

Question 14

Biotransformation of drugs is primarily directed to: Choices:

Accepted Answer

Convert lipid soluble drugs into non-lipid soluble metabolites — Biotransformation (metabolism) typically converts lipid-soluble drugs into more water-soluble (non-lipid soluble) metabolites, facilitating their excretion through urine or bile. ---

Question 15

The volume of distribution (Vd) relates to: Choices:

Accepted Answer

Single to a daily dose of an administrated drug — Volume of distribution is the theoretical volume necessary to contain the total amount of administered drug at the same concentration observed in blood plasma. It indicates the extent of drug distribution in body tissues. ---

Question 16

The reasons determining bioavailability are: Choices:

Accepted Answer

Extent of absorption and hepatic first-pass effect — Bioavailability is primarily determined by how much drug is absorbed and how much undergoes first-pass metabolism in the liver before reaching systemic circulation. ---

Question 17

All of the following statements about efficacy and potency are true EXCEPT: Choices:

Accepted Answer

The ED50 is a measure of drug's efficacy — ED50 (effective dose in 50% of population) is a measure of potency, not efficacy. Efficacy refers to the maximum effect a drug can produce, regardless of dose. ---

Question 18

Which of the following cytochrome P450 isoenzymes is involved in the metabolism of largest number of drugs in human beings and has been implicated in some dangerous drug interactions: Choices:

Accepted Answer

CYP 3A4 — CYP3A4 is responsible for metabolizing approximately 50% of all drugs and is frequently involved in clinically significant drug-drug interactions. ---

Question 19

The more concentrated the drug is the more potent it is. Choices:

Accepted Answer

False — Potency is determined by the drug's molecular characteristics and receptor interaction, not its concentration. Potency is a comparative term referring to the dose needed to produce an effect, not the concentration of the preparation. ---

Question 20

A prodrug is: Choices:

Accepted Answer

An inactive drug that is transformed in the body to an active metabolite — A prodrug is administered in an inactive or less active form and is metabolized in the body to produce the active drug. This approach can improve drug absorption, distribution, or reduce side effects. ---

Question 21

Which process is concerned with the blood brain barrier, tissue storage and plasma protein binding? Choices:

Accepted Answer

Distribution — Distribution involves the movement of drug from circulation to tissues and is affected by barriers (like blood-brain barrier), tissue binding, and plasma protein binding. ---

Question 22

Which of the following is pharmacokinetic parameter used to monitor the elimination phase of a drug? Choices:

Accepted Answer

Plasma half life — Plasma half-life (t½) is the time required for the plasma concentration of a drug to decrease by 50%. It is the primary parameter used to monitor and characterize drug elimination. ---

Question 23

The most commonly occurring conjugation reaction for drugs and their metabolites is: Choices:

Accepted Answer

Glucuronidation — Glucuronidation is the most common Phase II conjugation reaction, involving the addition of glucuronic acid to drugs or their metabolites, making them more water-soluble for excretion. ---

Question 24

What is the reason of complicated penetration of some drugs through brain-blood barrier? Choices:

Accepted Answer

Absence of pores in the brain capillary endothelium — The blood-brain barrier has tight junctions between endothelial cells with no pores, making it difficult for many drugs to penetrate. Only lipid-soluble drugs or those with specific transporters can cross easily. ---

Question 25

Which process involves the drug being metabolized in the liver before reaching systemic circulation? Choices:

Accepted Answer

Metabolism — This describes first-pass metabolism, where orally administered drugs are metabolized in the liver (or gut wall) before reaching systemic circulation, reducing bioavailability. ---

Question 26

Correct statements listing characteristics of a particular route of drug administration include all of the following EXCEPT: Choices:

Accepted Answer

Inhalation provides slow access to the general circulation — Inhalation actually provides rapid access to systemic circulation due to the large surface area and rich blood supply of the lungs, not slow access. ---

Question 27

Which process involves the passage of drug from the circulation to the tissue and site of its action? Choices:

Accepted Answer

Distribution — Distribution is the process by which a drug reversibly moves from the bloodstream into tissues and the site of action. ---

Question 28

There are two primary targets for most drugs are receptors and enzymes. Choices:

Accepted Answer

True — Most drugs exert their effects by interacting with specific receptors or enzymes. These are the two major molecular targets for drug action. ---

Question 29

High plasma protein binding: Choices:

Accepted Answer

Generally makes the drug long acting — Drugs highly bound to plasma proteins act as a reservoir, slowly releasing free drug as it is eliminated. This prolongs drug action and half-life. ---

Question 30

If you double the dose, which part of the illustration below will concern you more before continuing drug therapy? Choices:

Accepted Answer

E - F. F - G. G — A represents Cmax (peak concentration). Doubling the dose increases Cmax, bringing it closer to MTC (Minimum Toxic Concentration, labeled G), increasing the risk of toxicity. ---

Question 31

What is pharmacology? Choices:

Accepted Answer

All of the choices — Pharmacology is broadly the study of how chemical agents (drugs) affect biological systems, encompassing drug interactions with the body, effects, and toxicology. Multiple definitions can be correct. ---

Question 32

This illustration below is concerned with what aspect of drug therapy when caring for a patient? Choices:

Accepted Answer

Administered dose — The illustration displays pharmacokinetic characteristics (drug movement in the body), which are directly influenced by how much drug was administered, not the drug's pharmacodynamic effects. ---

Question 33

If the patient has a faster absorption, which part of the illustration below will concern you more before continuing drug therapy? Choices:

Accepted Answer

Faster absorption means the drug will reach therapeutic levels more quickly, resulting in a shorter onset time, which could be a concern for monitoring. -- — B represents onset time. Faster absorption means the drug will reach therapeutic levels more quickly, resulting in a shorter onset time, which could be a concern for monitoring. ---

Question 34

The plasma protein bound fraction of a drug: Choices:

Accepted Answer

Is not available for metabolism unless actively extracted by the liver — Only free (unbound) drug is available for metabolism, distribution, and elimination. Protein-bound drug is pharmacologically inactive unless the liver can actively extract it. ---

Question 35

The strength of the drug is related to the concentration of the drug. Choices:

Accepted Answer

True — Strength describes the amount/concentration of drug in a dosage form (e.g., 500 mg/tablet or 250 mg/5 mL). Higher concentrations mean greater strength of the preparation. ---

Question 36

If the patient has a faster elimination process, which part of the illustration below will concern you more before starting drug therapy? Choices:

Accepted Answer

E - F. F - G. G — E represents duration of action. Faster elimination shortens the duration of action, meaning drug concentrations may fall below the MEC (Minimum Effective Concentration) more quickly, potentially making the therapy subtherapeutic. --- Quiz Score: 35/36

MBPL3621 Introduction to Pharmacology Quiz 1 | MCQ Quiz | OmpathStudy Kenya

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