KAPS Pharmacokinetics and Biopharmaceutics 1

Question 1

Which pharmacokinetic parameter represents the time required for the plasma drug concentration to decrease by 50%?

Accepted Answer

Elimination half-life

Answer

Elimination half-life (t½) is the time required for the plasma concentration of a drug to fall by 50%, making it the parameter that directly describes elimination rate.

Question 2

What is the bioavailability of a drug administered intravenously?

Accepted Answer

100%

Answer

IV administration delivers the drug directly into systemic circulation, bypassing all absorption barriers and resulting in 100% bioavailability by definition.

Question 3

Which pharmacokinetic process describes the reversible transfer of a drug from the bloodstream into body tissues and organs?

Accepted Answer

Distribution

Answer

Distribution is the reversible transfer of drug from the bloodstream into body tissues, determined by factors such as lipophilicity, protein binding, and tissue blood flow.

Question 4

Volume of distribution (Vd) is BEST described as:

Accepted Answer

A hypothetical volume relating total drug in the body to plasma concentration

Answer

Volume of distribution is a hypothetical (not anatomical) volume representing the ratio of the total amount of drug in the body to its plasma concentration.

Question 5

Which factors PRIMARILY determine the rate of drug absorption from the gastrointestinal tract?

Accepted Answer

Drug lipophilicity and dissolution rate

Answer

Drug lipophilicity (fat solubility) and dissolution rate are the primary determinants of GI absorption rate, as they govern how readily a drug crosses intestinal membranes.

(KAPS) Knowledge Assessment of Pharmaceutical Sciences Practice Test

(KAPS) Knowledge Assessment of Pharmaceutical Sciences Practice Test

KAPS Pharmacokinetics and Biopharmaceutics 1