Pharmacology Pharmacokinetic Principles 2

Question 1

A drug with a large volume of distribution (Vd) is most likely doing which of the following?

Accepted Answer

Extensively distributed into peripheral tissues

Answer

A large Vd indicates the drug is widely distributed into tissues beyond the plasma compartment.

Question 2

Which of the following best defines bioavailability?

Accepted Answer

The fraction of administered drug that reaches systemic circulation unchanged

Answer

Bioavailability (F) is the fraction of an administered dose that reaches systemic circulation in active form.

Question 3

A drug undergoes significant first-pass metabolism. Which route of administration would BEST avoid this effect?

Accepted Answer

Intramuscular

Answer

Intramuscular injection delivers drug directly into systemic circulation, bypassing hepatic first-pass metabolism entirely.

Question 4

What is the clinical significance of a drug with a high extraction ratio?

Accepted Answer

Its clearance is highly sensitive to changes in liver blood flow

Answer

High extraction ratio drugs (>0.7) have flow-limited clearance, meaning hepatic blood flow changes significantly affect drug elimination.

Question 5

A patient has chronic kidney disease with a GFR of 20 mL/min. Which pharmacokinetic parameter is most directly affected?

Accepted Answer

Renal clearance

Answer

Renal clearance is directly reduced in CKD as glomerular filtration rate declines, prolonging drug half-life.

Pharmacology Practice Test