KAPS Pharmacokinetics and Biopharmaceutics 2

Question 1

Which statement about first-order drug elimination kinetics is TRUE?

Accepted Answer

A constant fraction of the drug present is eliminated per unit time

Answer

In first-order kinetics, a constant fraction (percentage) of the remaining drug is eliminated per unit time, so the rate of elimination is proportional to the current plasma concentration.

Question 2

Drug clearance is BEST defined as:

Accepted Answer

The volume of plasma completely cleared of drug per unit time

Answer

Clearance is the volume of plasma from which a drug is completely and irreversibly removed per unit time, typically expressed in mL/min or L/hr.

Question 3

Which equation correctly describes the relationship between elimination half-life (t½), volume of distribution (Vd), and clearance (Cl)?

Accepted Answer

t½ = 0.693 × Vd / Cl

Answer

The equation t½ = 0.693 × Vd / Cl shows that half-life increases as the volume of distribution increases and decreases as clearance increases.

Question 4

Which pharmacokinetic parameter is MOST useful for comparing total drug exposure between different dosing regimens or formulations?

Accepted Answer

Area under the plasma concentration-time curve (AUC)

Answer

The AUC represents total drug exposure over time and is the standard parameter used to compare bioavailability between different formulations or routes of administration.

Question 5

A drug has 25% oral bioavailability. If the desired IV dose is 80 mg, what approximate oral dose is needed to achieve equivalent systemic exposure?

Accepted Answer

320 mg

Answer

To achieve equivalent systemic exposure, divide the IV dose by the bioavailability fraction: 80 mg / 0.25 = 320 mg oral dose.

(KAPS) Knowledge Assessment of Pharmaceutical Sciences Practice Test

(KAPS) Knowledge Assessment of Pharmaceutical Sciences Practice Test

KAPS Pharmacokinetics and Biopharmaceutics 2