Pharm.D. Doctor of Pharmacy Pharmacokinetics and Pharmacodynamics

Question 1

Which pharmacokinetic parameter describes the volume of plasma cleared of a drug per unit time?

Accepted Answer

Clearance

Answer

Clearance (CL) is the pharmacokinetic parameter that represents the volume of plasma cleared of a drug per unit time, typically expressed in L/hr or mL/min.

Question 2

A drug has a half-life of 6 hours. Approximately how long does it take to reach steady-state concentration?

Accepted Answer

24–30 hours

Answer

Steady state is reached after approximately 4–5 half-lives, so a drug with a 6-hour half-life reaches steady state in about 24–30 hours.

Question 3

Which of the following best defines the volume of distribution (Vd)?

Accepted Answer

A proportionality constant relating plasma concentration to total drug in the body

Answer

Volume of distribution is an apparent proportionality constant that relates the total amount of drug in the body to the measured plasma concentration.

Question 4

What is the effect of first-pass metabolism on oral bioavailability?

Accepted Answer

Decreases bioavailability

Answer

First-pass (hepatic) metabolism reduces oral bioavailability by metabolizing a significant fraction of the drug before it reaches systemic circulation.

Question 5

Which pharmacodynamic concept describes the relationship between drug concentration and the maximum possible effect?

Accepted Answer

Emax model

Answer

The Emax model describes the relationship between drug concentration and effect, where Emax is the maximum achievable pharmacological response.

Pharm.D. Doctor of Pharmacy Practice Test

Pharm.D. Doctor of Pharmacy Practice Test

Pharm.D. Doctor of Pharmacy Pharmacokinetics and Pharmacodynamics