MPharm Master of Pharmacy Master of Pharmacy: Pharmacokinetics and Pharmacodynamics 3

Question 1

For a drug following two-compartment pharmacokinetics, the terminal elimination phase primarily reflects:

Accepted Answer

Redistribution from peripheral back to central compartment followed by elimination

Answer

In two-compartment models, the terminal beta phase represents slow redistribution of drug from peripheral tissues back to the central compartment, then elimination.

Question 2

Which enzyme system is primarily responsible for Phase I oxidative metabolism of most drugs in the liver?

Accepted Answer

Cytochrome P450 (CYP) enzymes

Answer

Cytochrome P450 enzymes are the major Phase I metabolizing enzymes responsible for oxidation, reduction, and hydrolysis of most drugs.

Question 3

Apparent clearance (CL/F) differs from true systemic clearance because it accounts for:

Accepted Answer

Incomplete bioavailability (F) after oral dosing

Answer

CL/F is apparent clearance calculated from oral dose data; dividing by F corrects for the fraction of dose that actually reaches systemic circulation.

Question 4

A drug that acts as a partial agonist at a receptor will:

Accepted Answer

Activate the receptor but with lower intrinsic efficacy than a full agonist

Answer

Partial agonists bind and activate receptors but have lower intrinsic efficacy, producing a submaximal response even at receptor saturation.

Question 5

Renal clearance of a drug exceeding glomerular filtration rate (GFR) suggests:

Accepted Answer

Active tubular secretion in addition to filtration

Answer

If CLrenal > GFR × fu, active tubular secretion must be occurring to add drug to the filtrate beyond what was filtered.

MPharm Master of Pharmacy Practice Test

MPharm Master of Pharmacy Practice Test

MPharm Master of Pharmacy Master of Pharmacy: Pharmacokinetics and Pharmacodynamics 3