Author Question: Which of the four phases of pharmacokinetics is concerned with solubility? a. Absorption b. ... (Read 64 times)

melina_rosy · **on:** Jul 23, 2018

Which of the four phases of pharmacokinetics is concerned with solubility?

a. Absorption
b. Distribution
c. Biotransformation
d. Elimination

Question 2

A patient who is due to begin treatment with a chemotherapeutic agent has questions regarding the drug's action. The health care provider explains to the patient that the majority of drugs are thought to act through which of the following mechanisms?

a. Changing the DNA structure in cells
b. Attaching to receptors on cell surfaces
c. Altering protein synthesis in the cell
d. Promoting cell growth

recede · **Reply #1 on:** Jul 23, 2018

Answer to Question 1

ANS: B
Distribution of a drug once it has been absorbed depends on its solubility. Lipid-soluble drugs rapidly cross cellular membranes because of the highly permeable nature of capillary endothelial membranes. Drugs that are insoluble in lipids are limited in their ability to pass capillary endothe-lial membranes and therefore have a restricted distribution.

Answer to Question 2

ANS: B
Pharmacodynamics is the study of the relationship between the concentration of a drug and the response obtained in the patient; in other words, how the drug acts at various sites in the body. Most often, the sites of action are receptors on the specific cell, tissue, or organ, where the drug initiates a chain of biochemical events that culminates in changes in physiologic functioning of the cell, or the activity of an enzyme or of an intracellular protein.