Pharmacology Pharmacokinetic Principles Questions and Answers

Question 1

A patient is administered an oral medication that undergoes significant first-pass metabolism. Which of the following statements accurately describes the consequence of this phenomenon?

Accepted Answer

The oral dose required to achieve a therapeutic effect will be higher than the intravenous dose.

Answer

The drug's bioavailability will be increased.

Answer

The drug will be rapidly distributed to peripheral tissues.

Answer

The drug's half-life will be significantly shortened.

Question 2

A drug has a very large apparent volume of distribution (Vd) of 400 L in a 70 kg adult. What does this indicate about the drug's distribution characteristics?

Accepted Answer

It is extensively distributed into tissues outside the plasma.

Answer

It is largely confined to the intravascular space.

Answer

It is highly bound to plasma proteins.

Answer

It is a large molecule that cannot easily cross cell membranes.

Question 3

A patient with end-stage renal disease requires a medication that is primarily eliminated unchanged by the kidneys. Which pharmacokinetic parameter will be most significantly altered in this patient?

Accepted Answer

Half-life

Answer

Absorption

Answer

Volume of distribution

Answer

First-pass metabolism

Question 4

Which of the following describes a key characteristic of zero-order elimination kinetics?

Accepted Answer

A constant amount of drug is eliminated per unit of time.

Answer

The rate of elimination is proportional to the plasma drug concentration.

Answer

The drug's half-life is constant regardless of the dose.

Answer

The clearance rate increases as the plasma drug concentration increases.

Question 5

Drug metabolism is often categorized into Phase I and Phase II reactions. Which of the following is a primary goal of Phase I reactions?

Accepted Answer

Introducing or exposing a functional group on the parent drug.

Answer

Conjugating the drug with an endogenous molecule to increase its size.

Answer

Directly excreting the unchanged drug into the bile.

Answer

Decreasing the drug's polarity to enhance tissue distribution.

Question 6

After approximately how many half-lives does a drug administered via continuous infusion reach a steady-state concentration in the plasma?

Accepted Answer

4-5 half-lives

Answer

1-2 half-lives

Answer

2-3 half-lives

Answer

6-7 half-lives