Pharm.D. Doctor of Pharmacy Pharmacokinetics and Pharmacodynamics 2

Question 1

Which equation is used to calculate drug clearance from area under the curve (AUC)?

Accepted Answer

CL = Dose / AUC

Answer

Clearance is calculated as CL = Dose / AUC (after IV dosing), relating the administered dose to total drug exposure.

Question 2

Which type of drug interaction involves competition for the same plasma protein binding site?

Accepted Answer

Pharmacokinetic displacement

Answer

Pharmacokinetic displacement occurs when two drugs compete for the same plasma protein binding sites, potentially increasing free drug concentration of one.

Question 3

The therapeutic index (TI) is calculated as:

Accepted Answer

TD50 / ED50

Answer

The therapeutic index is TD50 / ED50, representing the ratio of the toxic dose to the effective dose — a higher TI indicates a safer drug.

Question 4

Renal clearance of a drug is primarily affected by which three processes?

Accepted Answer

Filtration, secretion, reabsorption

Answer

Renal drug clearance depends on glomerular filtration, active tubular secretion, and tubular reabsorption of the drug.

Question 5

Which cytochrome P450 enzyme is most responsible for the metabolism of the majority of clinically used drugs?

Accepted Answer

CYP3A4

Answer

CYP3A4 is the most abundant hepatic CYP enzyme and is responsible for metabolizing approximately 50% of all clinically used drugs.

Pharm.D. Doctor of Pharmacy Practice Test

Pharm.D. Doctor of Pharmacy Practice Test

Pharm.D. Doctor of Pharmacy Pharmacokinetics and Pharmacodynamics 2