KAPS Pharmacokinetics and Biopharmaceutics 3

Question 1

Which route of administration MOST effectively avoids first-pass hepatic metabolism?

Accepted Answer

Sublingual tablet

Answer

Oral tablet (swallowed)

Answer

Enteric-coated oral capsule

Answer

Extended-release oral formulation

Question 2

Why is the protein binding of a drug clinically significant?

Accepted Answer

Only the free (unbound) drug fraction is pharmacologically active and available for distribution

Answer

Protein-bound drug is excreted more rapidly by the kidneys

Answer

Protein binding enhances drug metabolism in the liver

Answer

Protein-bound drug has a smaller volume of distribution

Question 3

Which formulation strategy would MOST effectively increase the oral bioavailability of a poorly water-soluble drug (BCS Class II)?

Accepted Answer

Micronization to reduce particle size

Answer

Increasing tablet hardness

Answer

Adding an enteric coating

Answer

Increasing filler excipient concentration

Question 4

Enterohepatic recirculation refers to:

Accepted Answer

Drug cycling between the intestine and liver via biliary excretion followed by intestinal reabsorption

Answer

Drug movement from plasma into intestinal mucosal cells

Answer

First-pass metabolism of drugs in the intestinal wall (gut wall metabolism)

Answer

Active secretion of drugs from bloodstream into the intestinal lumen

Question 5

The Henderson-Hasselbalch equation is MOST useful in pharmacokinetics for predicting:

Accepted Answer

The degree of ionization of a drug at a given pH

Answer

Drug metabolism rates at various liver blood flows

Answer

Drug-receptor binding affinity constants

Answer

Changes in volume of distribution with age

Question 6

Which statement about zero-order elimination kinetics is CORRECT?

Accepted Answer

A fixed absolute amount of drug is eliminated per unit time

Answer

The rate of elimination is proportional to the plasma drug concentration

Answer

The elimination half-life is constant regardless of drug concentration

Answer

Zero-order kinetics typically occurs at low, sub-therapeutic drug concentrations

Question 7

A patient with severe renal impairment is prescribed a drug that is 90% renally eliminated unchanged. What is the MOST appropriate dosing adjustment?

Accepted Answer

Reduce the dose or extend the dosing interval to prevent toxicity

Answer

No adjustment needed since the liver can compensate

Answer

Increase the dose to overcome impaired clearance

Answer

Switch to a higher-frequency dosing schedule