Question

Half-life is defined as:

A. Halfway to the expiration date for a drug
B. The time it takes the body to eliminate 50% of a drug
C. The dose of a a drug that is effective in 50% of patients
D. One-half the volume of distribution
E. None of the above

Answer 1

Half-life is the time required for the concentration of a substance to decrease to half its initial value, which includes the decaying of radioactive nuclei or the elimination of a drug from the body.

Step-by-step explanation:

Half-life is defined as the period of time it takes for the concentration of a reactant, or the amount of a radioactive substance, to decrease to one-half of its initial value. This concept is particularly vital in nuclear chemistry where it describes the time required for half of the radioactive nuclei in a sample to undergo decay.

Similarly in pharmacology, half-life refers to the time it takes for the body to eliminate 50% of a drug. Therefore, the correct answer to the question is B: The time it takes the body to eliminate 50% of a drug.