CHAPTER 7: Toxicokinetics

Chapter 7. Toxicokinetics

Regarding the two-compartment model of classic toxicokinetics, which of the following is true?

a. There is rapid equilibration of chemical between central and peripheral compartments.

b. The logarithm of plasma concentration versus time data yields a linear relationship.

c. There is more than one dispositional phase.

d. It is assumed that the concentration of a chemical is the same throughout the body.

e. It is ineffective in determining effective doses in toxicity studies.

When calculating the fraction of a dose remaining in the body over time, which of the following factors need not be taken into consideration?

a. half-life.

b. initial concentration.

c. time.

d. present concentration.

e. elimination rate constant.

All of the following statements regarding apparent volume of distribution (V_d) are true EXCEPT:

a. V_d relates the total amount of chemical in the body to the concentration of chemical in the plasma.

b. V_d is the apparent space into which an amount of chemical is distributed in the body to result in a given plasma concentration.

c. A chemical that usually remains in the plasma has a low V_d.

d. V_d will be low for a chemical with high affinity for tissues.

e. V_d can be used to estimate the amount of chemical in the body if the plasma concentration is known.

Chemical clearance:

a. is independent of V_d.

b. is unaffected by kidney failure.

c. is indirectly proportional to V_d.

d. is performed by multiple organs.

e. is not appreciable in the GI tract.

A chemical with which of the following half-lives (T_1/2) will remain in the body for the longest period of time when given equal dosage of each?

a. T_1/2 = 30 min.

b. T_1/2 = 1 day.

c. T_1/2 = 7 h.

d. T_1/2 = 120 s.

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