CH 2: Drugs & the Body

Question 1

absorption

Answer 1

• what happens to a drug from the time it enters the body until it enters the circulating fluid
• IV administration causes the drug to directly enter the circulating blood

Question 2

active transport

Answer 2

movement of substances across a cell membrane across the concentration gradient

Question 3

chemotheapeutic agents

Answer 3

synthetic chemicals used to interfere w/ the functioning of foreign cell populations

Question 4

critical concentration

Answer 4

the amount of a drug needed to cause a therapeutic effect

Question 5

distribution

Answer 5

movement of a drug to body tissues

Question 6

enzyme induction

Answer 6

process by which the presence of a chemical that is biotransformed by a particular enzyme system in the liver causes increased activity of that enzyme system

Question 7

excretion

Answer 7

• removal of a drug from the body

- primarily occurs in the kidneys; can also occur through skin, lungs, bile, or feces

Question 8

first-pass effect

Answer 8

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

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

Question 10

half-life

Answer 10

time it takes for the amount of drug in the body to decrease to 1/2 of the peak level it previously 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

use of a higher dose than that which is usually used for tx to allow the drug to reach the critical concentration sooner

Question 13

passive diffusion

Answer 13

movement of substances across a semi-permeable membrane w/ the concentration gradient

Question 14

pharmacodynamics

Answer 14

how the drug affects the body

Question 15

pharmacogenomics

Answer 15

study of genetically determined variations in the response to drugs

Question 16

pharmacokinetics

Answer 16

how the body acts on the drug

Question 17

placebo effect

Answer 17

if a person perceives a drug will be effective, the drug is more likely to actually be effective

Question 18

receptor sites

Answer 18

specific areas on cell membranes that react w/ certain chemicals to cause an effect w/in the cell

Question 19

selective toxicity

Answer 19

property of a chemotherapeutic agent that affects only systems found in foreign cells w/o affecting healthy human cells

Question 20

agonists

Answer 20

drugs that interact directly w/ receptor sites to cause the same activity natural chemicals would cause at that site

Question 21

competitive antagonist

Answer 21

drugs that react w/ receptor sites to block normal stimulation, producing no effect

Question 22

noncompetitive antagonist

Answer 22

drugs that react w/ receptor sites to prevent reaction of another chemical w/ a different receptor site

Question 23

vasoconstriction

Answer 23

constricted blood vessels

Question 24

cross-tolerance

Answer 24

resistance to drugs w/in the same class