B.Pharm. Bachelor of Pharmacy Biopharmaceutics & Pharmacokinetics 2

Question 1

The therapeutic index (TI) of a drug is defined as the ratio of:

Accepted Answer

LD50 to ED50

Answer

The therapeutic index is calculated as LD50/ED50; a higher TI indicates a greater margin of safety between the lethal dose and the effective dose of a drug.

Question 2

Zero-order kinetics means that the rate of drug elimination is:

Accepted Answer

Constant and independent of plasma drug concentration

Answer

In zero-order kinetics, a constant amount of drug is eliminated per unit time regardless of plasma concentration, typically occurring when elimination mechanisms are saturated (e.g., ethanol, phenytoin at high doses).

Question 3

The absorption rate constant (Ka) is used to describe:

Accepted Answer

The speed at which a drug is absorbed from the site of administration into systemic circulation

Answer

Ka (absorption rate constant) quantifies how quickly a drug moves from its site of administration into the systemic circulation, influencing Tmax and Cmax values.

Question 4

The Area Under the Curve (AUC) in pharmacokinetics represents:

Accepted Answer

Total drug exposure over time

Answer

AUC (Area Under the plasma concentration-time Curve) represents the total drug exposure over time and is directly proportional to the total amount of drug that reaches systemic circulation.

Question 5

Highly plasma protein-bound drugs have a characteristically:

Accepted Answer

Small volume of distribution and prolonged half-life

Answer

Drugs extensively bound to plasma proteins remain in the vascular compartment (small Vd), are protected from metabolism/excretion, and have a prolonged half-life due to reduced free drug available for elimination.

B.Pharm. Bachelor of Pharmacy Practice Test

B.Pharm. Bachelor of Pharmacy Practice Test

B.Pharm. Bachelor of Pharmacy Biopharmaceutics & Pharmacokinetics 2