Chapter 2

Question 1

Absorption:

Answer 1

what happens to a drug from the time it enters the body until it enters the circulating fluid.

Question 2

Active transport:

Answer 2

the movement of substances across a cell membrane; this process requires the use of energy.

Question 3

Chemotherapeutic agents:

Answer 3

synthetic chemicals used to interfere with the functioning of foreign cell populations, causing cell death; this term is frequently used to refer to the drug therapy of neoplasms, but it also refers to drug therapy affecting any foreign cell.

Question 4

Critical concentration:

Answer 4

the concentration a drug must reach in the tissues that respond to the particular drug to cause the desired therapeutic effect.

Question 5

Distribution:

Answer 5

movement of a drug to body tissues; the places where a drug may be distributed depend on the drug’s solubility, perfusion of the area, cardiac output, and binding of the drug to plasma proteins.

Question 6

Enzyme induction:

Answer 6

process by which the presence of a chemical causes increased activity of an enzyme system.

Question 7

Excretion:

Answer 7

removal of a drug from the body; routes include the kidneys, skin, lungs, bile, and feces.

Question 8

First-pass effect:

Answer 8

a phenomenon in which drugs given orally are carried directly to the liver after absorption, where they may be largely inactivated by liver enzymes before they can enter the general circulation.

Question 9

Glomerular filtration:

Answer 9

the passage of water and water-soluble components from the plasma into the renal tubule.

Question 10

Half-life:

Answer 10

the time it takes for the amount of drug in the body to decrease to one half of the peak level it achieved.

Question 11

Hepatic microsomal system:

Answer 11

liver enzymes tightly packed together in the hepatic intracellular structure, responsible for the biotransformation of chemicals, including drugs.

Question 12

Loading dose:

Answer 12

a dose higher than what is usually used for treatment, administered to allow the drug to reach the critical concentration sooner.

Question 13

Passive Diffusion:

Answer 13

movement of substances across a semipermeable membrane with the concentration gradient; this process does not require energy.

Question 14

Pharmacodynamics:

Answer 14

the study of the interactions between the chemical components of living systems and the foreign chemicals, including drugs, that enter living organisms; the way a drug affects a body.

Question 15

Pharmacogenomics:

Answer 15

the study of genetically determined variations in the response to drugs.

Question 16

Pharmacokinetics:

Answer 16

the way a medication travels through the body, including absorption, distribution, biotransformation, and excretion; how the body acts on a drug.

Question 17

Placebo effect:

Answer 17

documented effect of the mind on drug therapy; if a person perceives that a drug will be effective, the drug is much more likely to actually be effective.

Question 18

Receptor sites:

Answer 18

specific areas on cell membranes that react with certain chemicals to cause an effect within the cell.

Question 19

Selective toxicity:

Answer 19

property of a chemotherapeutic agent that affects only systems found in foreign cells without affecting healthy human cells (e.g., specific antibiotics can affect certain proteins or enzyme systems used by bacteria but not those used by human cells).

Question 20

Therapeutic index:

Answer 20

ratio comparing the blood concentration at which a drug becomes toxic with the concentration at which the drug is effective.