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

mvmt of substances across a cell membrane against the concentration gradient; this process requires the use of energy and important for drug excretion in the kidney

Question 3

chemotherapeutic agents

Answer 3

synthetic chemicals used to interfere w/ the functioning of foreign cell populations; frequently used to refer to drug therapy of neoplasms, but also any 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

mvmt 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 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, but can occur thru the skin, lungs, bile or 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; oral drugs are often given in higher doses b/c of this early breakdown

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 previously achieved

Question 11

hepatic microsomal system

Answer 11

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

Question 12

loading dose

Answer 12

use of a higher dose than what is usually used for Tx to allow the drug to reach the critical concentration sooner (high dose initially if there is a prolonged period to reach critical concentration and need action now) (*pharmacokinetics)

Question 13

passive diffusion

Answer 13

mvmt of substances across semipermeable membrane w/ the concentration gradient; this process does not require energy; is the major process of dug absorption into the body

Question 14

pharmacodynamics

Answer 14

HOW THE DRUG AFFECTS THE BODY.
the study of the interactions b/w the chemical components of living systems and the foreign chemicals, including drugs, that enter living organisms; the way a drug affects the body

Question 15

pharmacogenomics

Answer 15

the study of genetically determined variations int eh response to drugs

Question 16

pharmacokinetics

Answer 16

HOW THE BODY ACTS ON THE DRUG.

the way the body deals w/ a drug, including absorption, distribution, biotransformation, and excretion

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 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 (e.g. specific antibiotics can affect certain proteins or enzyme systems used by bacteria but not by human cells) Ex. Penicillin

Question 20

In what 4 ways do drugs work?

Answer 20

1. replace or substitute missing chemicals, 2. increase/stimulate certain cellular activities, 3. Depress/slow cellular activities, 4. interfere w/ function of foreign cells

Question 21

How do drugs act on the cell membranes?

Answer 21

They fit in receptor sites where certain chemicals cause an effect w/in the cell. Nearby enzymes break down the reacting chemicals and open the receptor site for further stimulation. (*pharmacodynamics)

Question 22

Agonist drugs

Answer 22

Drugs that interact directly w/ receptor sties to cause the same activity that natural chemicals would cause at that site. (*pharmacodynamics)

Question 23

What do monoamine oxidase (MAO) inhibitors block?

Answer 23

The breakdown of NE by the enzyme MAO, which allows prolonged effects that can be therapeutic (relieving depression) or adverse (incr HR). (Normally MAO breaks down NE, removes it from the receptor site, and recycles the components to form new NE.) (*pharmacodynamics)

Question 24

Competitive antagonists

Answer 24

drugs that react w/ receptor sites to block normal stimulation, producing no effect. (Ex. curare occupies receptor sites for acetylcholine (ACh)) (*pharmacodynamics)

Question 25

Noncompetitive antagonists

Answer 25

Drugs that react w/ specific receptor sites on a cell, by reacting there it prevents the reaction of another chemical w/ a different receptor site on that cell. (*pharmacodynamics)

Question 26

In what 4 ways does the body deal with drugs?

Answer 26

Absorption, distribution, metabolism (biotransformation), and excretion (*pharmacokinetics)

Question 27

How much of a drug is needed to cause a therapeutic effect?

Answer 27

It should maintain the critical concentration. Too much of a drug will produce toxic (poisonous) effects, and too little will not produce the desired therapeutic effects.

Question 28

Pharmacokinetics is how the body acts on the drug. What is considered in the clinical setting ?

Answer 28

Onset of drug action, drug half-life, timing of the peak effect, duration of drug effects, metabolism of drug and site of excretion.

Question 29

Dynamic equilibrium

Answer 29

The actual concentration that a drug reaches in the body resulting from absorption, distribution, metabolism and excretion.

Question 30

Where in the body can drugs be absorbed?

Answer 30

GI TRACT: oral or rectal (oral is less invasive, cheaper and most often used in clinical practice)
VEIN: IV administration causes the drug to directly enter the circulating blood, bypassing many complications of absorption from other routes

Question 31

How are most drugs distributed?

Answer 31

Most drugs are bound to some extent to proteins in the blood to be carried into circulation. The protein–drug complex is relatively large and must be freed from the protein’s binding site at the tissues.Some drugs are tightly bound and are released very
slowly. These drugs have a very long duration of action because they are not free to be broken down or excreted.

Question 32

What kind of drugs are not able to pass the blood-brain barrier?

Answer 32

Lipid soluble. Cross the BBB affects the CNS. This is clinically significant in treating a brain infection w/ antibiotics. Almost all antibiotics are not lipid soluble and cannot cross the blood–brain barrier.

Question 33

Which organ is the most important in drug breakdown in the body?

Answer 33

The liver. The breakdown helps prevent adverse reactions in the body.

Question 34

Why is the recommended dose for oral drugs higher than parenteral drugs?

Answer 34

b/c of the first-pass effect. a large percentage never reaches the tissues b/c of the breakdown in the liver

Question 35

Which organ has the most important role in excretion of medication?

Answer 35

The kidney. Other routes of excretion are the skin, saliva, lungs, bile, and feces.

Question 36

How is half-life affected? What does it effect clinically?

Answer 36

Absorption, distribution, metabolism, excretion

Dosing schedules.

Question 37

What factors influence drug effects?

Answer 37

Weight, age, gender, allergies, diseases, patient attitude, environmental, drug tolerance, drug interactions (see pg 26)

Question 38

What weight do most drug recommendation target?

Answer 38

150-pound person. So a heavier person may require more and a smaller person may require less.

Question 39

Why is age a factor in influence of drug effects?

Answer 39

b/c children metabolize many drugs differently than adults do

Question 40

Why is gender a factor in influence of drug effects?

Answer 40

Men have more vascular muscles and IM injections have faster effects. Women have more fat so drugs that deposit there are more slowly released.

Question 41

What type effects can occur w/ Drug-to-Drug Interactions?

Answer 41

can occur any time 2 or more drugs are taken together.
ANTAGONISTIC: 2 drugs cancel each other out
ADDITIVE: 2 drugs w/ similar mechanisms increase the effects
SYNERGISTIC: 2 drugs w/ different mechanisms have greater effect together

Question 42

Why are drugs best taken on an empty stomach? When are they not?

Answer 42

B/c of drug-food interaction. Vitamin K and dairy can cancel the drug’s effect or render ineffective.
*there are some that irritate the GI tract and need food