Pharmacocinétique et absorption Practice Quiz (22 questions)

1. Before administering a medication, which checks are required by the five rights?

A. The right medication, diagnosis, prescriber, dose, and duration

B. The right medication, patient, allergy status, pharmacy, and route

C. The right medication, time, patient, dose, and route

D. The right patient, room, time, formulation, and monitoring plan

Answer: (C)

Explanation

The five rights require checking the medication, time, patient, dose, and administration route before each administration. Checking a diagnosis or prescriber may be relevant to care, but those checks do not replace the five specified rights.

2. What distinguishes an active pharmaceutical ingredient from an excipient?

A. It is the packaging material that protects the medication from damage.

B. It is the substance that determines how quickly the medication is eliminated.

C. It is the inert component that helps the medication be administered.

D. It is the molecule responsible for the medication’s pharmacological effect.

Answer: (D)

Explanation

The active pharmaceutical ingredient is the active molecule responsible for the medication’s pharmacological effect. An excipient instead facilitates the incorporation or administration of the active ingredient and is presented as inert.

3. What is the role of an excipient in a medication?

A. It facilitates incorporating or administering the active ingredient.

B. It determines which patient should receive the medication.

C. It removes the medication from the body after it acts.

D. It produces the medication’s principal pharmacological effect.

Answer: (A)

Explanation

An excipient is presented as an inert component that helps incorporate or administer the active ingredient. Producing the principal pharmacological effect is the role of the active ingredient, not the excipient.

4. A researcher investigates how a medication moves through the body, while another investigates its effect on the body; which fields are they studying, respectively?

A. Pharmacodynamics, then pharmacokinetics

B. Pharmaceutical formulation, then pharmacology

C. Pharmacokinetics, then pharmacodynamics

D. Pharmacology, then pharmaceutical formulation

Answer: (C)

Explanation

Pharmacokinetics studies a medication’s fate in the body, whereas pharmacodynamics studies the active ingredient’s effect on the body. Reversing these fields confuses the medication’s movement with its effects.

5. Which sequence of processes describes a medication’s pharmacokinetic fate in the body?

A. Distribution, absorption, elimination, and metabolism

B. Absorption, distribution, metabolism, and elimination

C. Absorption, metabolism, distribution, and elimination

D. Metabolism, distribution, absorption, and elimination

Answer: (B)

Explanation

Pharmacokinetics describes the medication’s fate through absorption, distribution, metabolism, and elimination. Metabolism occurs after distribution in the stated sequence, so placing it before distribution changes the order.

6. After a medication has been absorbed, what is the next step in its pharmacokinetic pathway?

A. Distribution through the body

B. Metabolism in the body

C. Elimination from the body

D. Administration at the site of use

Answer: (A)

Explanation

The pathway proceeds from absorption to distribution, followed by metabolism and elimination. Metabolism is a later step, rather than the process immediately following absorption.

7. What does absorption mean in pharmacokinetics?

A. Chemical transformation of medication into other substances within the body

B. Passage of unchanged medication from its administration site into systemic circulation

C. Removal of medication from the body after it has circulated

D. Movement of medication from systemic circulation into the tissues where it acts

Answer: (B)

Explanation

Absorption is the passage of a medication, unchanged, from its administration site into the general circulation. Movement from the circulation into tissues describes distribution instead.

8. A clinician is selecting an administration route for a patient; which set of considerations is relevant to studying absorption?

A. Target, desired onset or duration, medication properties, and patient characteristics

B. Diagnosis, prescriber preference, medication cost, and pharmacy location

C. Patient age, medication packaging, storage temperature, and prescription format

D. Target, medication brand, treatment setting, and refill schedule

Answer: (A)

Explanation

Absorption studies inform route selection based on the target, desired speed or duration of effect, the medication’s physicochemical properties, and patient characteristics. Factors such as pharmacy location and prescription format do not constitute the specified absorption considerations.

9. What distinguishes a parenteral route of drug administration from an enteral route?

A. A parenteral route involves a breach of tissue, whereas an enteral route uses the digestive tract.

B. A parenteral route uses the digestive tract, whereas an enteral route involves a breach of tissue.

C. A parenteral route avoids tissue penetration, whereas an enteral route bypasses the digestive tract.

D. A parenteral route is defined by absorption into blood, whereas an enteral route is defined by local action.

Answer: (A)

Explanation

Parenteral routes involve an effraction, while enteral routes use the digestive tract. The second choice reverses the defining features of the two route categories.

10. Which set consists entirely of parenteral routes of administration?

A. Intravenous, subcutaneous, intramuscular, and intra-arterial

B. Oral, rectal, intravenous, and subcutaneous

C. Sublingual, oral, intramuscular, and intra-arterial

D. Rectal, sublingual, subcutaneous, and intramuscular

Answer: (A)

Explanation

The listed parenteral routes are intravenous, subcutaneous, intramuscular, and intra-arterial. The other sets include oral, rectal, or sublingual routes, which are not part of that listed group.

11. What is the main function of the blood-brain barrier?

A. It filters exchanges between the bloodstream and the central nervous system.

B. It promotes the passage of medicines from the bloodstream into intestinal cells.

C. It filters exchanges between the digestive tract and the bloodstream.

D. It prevents medicines from reaching the fetus through the placenta.

Answer: (A)

Explanation

The blood-brain barrier filters exchanges between the circulation and the central nervous system. The digestive tract-to-blood exchange concerns the intestinal barrier, not the blood-brain barrier.

12. A medication taken during the first trimester is associated with a risk of fetal malformations; what type of risk is this?

A. A teratogenic risk, associated with later trimesters and fetal intoxication

B. A fetotoxic risk, associated with later trimesters and malformations

C. A teratogenic risk, associated with the first trimester and malformations

D. A fetotoxic risk, associated with the first trimester and malformations

Answer: (C)

Explanation

Teratogenic risk is associated with the first trimester and the possibility of malformations. Fetotoxic risk is associated with the second and third trimesters and fetal intoxication.

13. What does the first-pass effect describe?

A. Drug movement from the administration site to the target tissue

B. Drug passage through a cell membrane during absorption

C. Drug filtration between the bloodstream and the central nervous system

D. Drug loss as it passes through cells, including cells in the intestine or liver

Answer: (D)

Explanation

The first-pass effect is the loss of drug during passage through cells, notably in the intestine or liver. Movement to a target site describes transfer, rather than first-pass loss.

14. Which description distinguishes passive diffusion from active transport when a drug moves against its concentration gradient?

A. Passive diffusion proceeds without energy, while active transport uses a membrane carrier and energy for movement against the gradient.

B. Passive diffusion uses a membrane carrier, while active transport proceeds without energy along the gradient.

C. Both processes require energy, but only passive diffusion uses a specific membrane carrier.

D. Both processes proceed without energy, but active transport moves against the gradient.

Answer: (A)

Explanation

Passive diffusion occurs naturally without energy, whereas active transport uses a membrane carrier and requires energy when moving against the gradient. A plausible confusion is to assume that movement along a gradient requires active transport, but passive diffusion follows the gradient without energy.

15. A drug crosses a membrane through a specific carrier that becomes saturated and can move the drug against its gradient. Which transport mechanism is involved?

A. Active transport, which can saturate and use energy to move a drug against its gradient.

B. Bulk transport, which is nonspecific and moves drugs down their concentration gradient.

C. Passive diffusion, which can saturate and use energy to move a drug against its gradient.

D. Facilitated diffusion, which moves a drug against its gradient without using energy.

Answer: (A)

Explanation

Active transport is specific and saturable, and it can use energy to move a drug against its gradient. Passive diffusion is the most plausible alternative, but it follows the gradient and is not saturable.

16. Which set of factors influences a drug’s passage across a membrane by passive diffusion?

A. Blood flow, intestinal surface area, first-pass loss, and efflux pump abundance.

B. Concentration gradient, carrier saturation, energy use, and competition between drugs.

C. Concentration gradient, molecular weight, lipophilicity, and whether the drug is uncharged.

D. Carrier specificity, energy availability, saturation, and competition with other drugs.

Answer: (C)

Explanation

Passive diffusion depends on the concentration gradient, molecular weight, lipophilicity, and the drug’s uncharged character. Carrier saturation and competition are associated with active transport rather than passive diffusion.

17. Why is oral drug absorption generally more favorable in the intestine than in the stomach?

A. The intestinal environment, absorption surface, and vascularization are more favorable for absorption.

B. The intestinal pH makes every drug uncharged, regardless of its chemical properties.

C. The stomach has a larger absorption surface and greater vascularization than the intestine.

D. The stomach prevents drug loss during passage, while the intestine increases first-pass loss.

Answer: (A)

Explanation

Absorption is generally more favorable in the intestine because of differences in pH, its larger absorption surface, and greater vascularization. A larger stomach surface would explain the comparison incorrectly; the intestine has the greater surface and vascularization.

18. Which approximate pH comparison is used to explain differences in drug charge and membrane passage between the stomach and intestine?

A. Both the stomach and intestine are around pH 1–2.

B. The stomach is around pH 1–2, while the intestine is around pH 6–7.

C. Both the stomach and intestine are around pH 6–7.

D. The stomach is around pH 6–7, while the intestine is around pH 1–2.

Answer: (B)

Explanation

The stomach is described as having a pH of approximately 1–2, compared with approximately 6–7 in the intestine. Reversing these values is a plausible mix-up, but assigns the intestinal pH range to the stomach.

19. After intestinal absorption, which route does a drug follow before reaching the general circulation?

A. Mesenteric veins, then the caval system, through the liver, and into the general circulation via the portal vein.

B. Portal vein, then the mesenteric veins, through the kidneys, and into the general circulation via the caval system.

C. Mesenteric veins, then the portal vein, through the liver, and into the general circulation via the caval system.

D. Lymphatic vessels, then the portal vein, through the liver, and into the general circulation via the mesenteric veins.

Answer: (C)

Explanation

The drug enters the mesenteric veins, passes into the portal vein, traverses the liver, and then reaches general circulation through the caval system. A plausible route error is to reverse the mesenteric and portal veins, which changes the stated sequence.

20. How can a P-glycoprotein efflux pump affect a drug inside a cell?

A. It can carry the drug through the cell membrane against its gradient by passive diffusion.

B. It can eject the drug from the cell, limiting the drug’s access to its destination.

C. It can draw the drug into the cell, increasing the drug’s access to its destination.

D. It can break the drug down inside the cell, preventing its movement into the bloodstream.

Answer: (B)

Explanation

An efflux pump such as P-glycoprotein rejects a drug from the cell and can therefore limit its access to its destination. The opposite action—drawing the drug into the cell—describes influx rather than efflux.

21. What does the area under a blood concentration–time curve represent?

A. The time required for half the medication to leave the bloodstream, expressed in hours

B. The organism’s exposure to the medication, expressed in milligrams per liter per hour

C. The medication’s peak blood concentration, expressed in milligrams per liter

D. The fraction of the dose absorbed, expressed as a percentage

Answer: (B)

Explanation

The area under the concentration–time curve represents the organism’s exposure to the medication, with units of milligrams per liter per hour. Peak concentration describes a single point on the curve rather than its area.

22. A researcher compares how much of a drug reaches the blood after oral administration with how much reaches it through a non-intravenous reference route. What type of bioavailability is being assessed?

A. Systemic clearance, which compares how quickly the drug is removed after two routes

B. Absolute bioavailability, which compares the studied route with an intravenous reference route

C. Relative bioavailability, which compares the studied route with a non-intravenous reference route

D. Peak bioavailability, which compares the highest concentrations produced by two routes

Answer: (C)

Explanation

Relative bioavailability compares the amount reaching the blood through a studied route with the amount from a reference route other than intravenous. Absolute bioavailability uses intravenous administration as the reference.