Chapter 1

Question 1

Systematic vs CNS Administration

Answer 1

Systematic: drug given in accordance to body weight

CNS: Given in terms of absolute amount (#of molecules/mole)

Question 2

Dose response curves are in a _____scale

Answer 2

logarithmic

Question 3

A Binary variable study will appear on a DRC as:

Answer 3

2 separate curves.

Question 4

Formula for drug therapeutic index

Answer 4

TI= LD50/ED50

Question 5

The higher the TI, the ____the drug

Answer 5

safer.

Question 6

Efficacy

Answer 6

differences in MAXIMUM effect that drugs will produce at any dose.

Question 7

Potentcy:

Answer 7

Differences in the ED50 of 2 drugs.

Question 8

A drug with a LOW Ed50 has a ____ potency

Answer 8

high

Question 9

ED50

Answer 9

MEDIAN EFFECTIVE DOSE-dose effective in 50% of the population

Question 10

using a DRC, how can you tell if drug antagonism is occurring?

Answer 10

Drug antagonism: when the presence of one drug inhibits the affect of another
- can be seen if the DRC of a drug has shifted right (ED50 increased, need more drug to be effective) after the addition of another drug

Question 11

Additive effect

Answer 11

When taking 2 drugs shifts the DRC curve to the left, decreasing the original effect

Question 12

Superadditive effect

Answer 12

if the drugs together have a greater affect than intended

Question 13

What is a parenteral route of administration

Answer 13

involves injection through the skin.

Question 14

T/F Oil based vehicles speed up the rate of absorption

Answer 14

false, oil based vehicles slow the rate of absorption and allow the drugs effect to take place over several days.

Question 15

4 main systemic parental routes of administration

Answer 15

1) subcutaneous
2) intramuscular
3) intraperitoneal
4) intravenous

Question 16

Intrathecal injection

Answer 16

drug administered via injection into general nervous system.

Question 17

Intracerebroventricular injection

Answer 17

injection directly into the brains ventricle system, gets injected into “aquaduct” and gets distributed throughout entire brain

Question 18

Intracerebral injection

Answer 18

injection in which a drug is administered to a specific brain tissue.

Question 19

Pros and Cons of Parenteral CNS administration

Answer 19

• not body weight dependent
• good for drugs that won’t trigger a response if injected into body (won’t pass blood brain barrier)
• good for molecules that are too big to reach the blood vessels in brain.
• not ideal because it involves drilling holes in skulls–> invasive.

Question 20

2 Factors that effect the rate of absorption

Answer 20

1) increased blood volume near region of injection

2) heat

Question 21

Drugs are absorbed into Bloodstream via _____ in the capillaries

Answer 21

pores in the capillaries.

Question 22

Slowest method of parental injection… fastest?

Answer 22

subcutaneous, intravenous.

Question 23

Depot injection

Answer 23

drug administered using oil based vehicle in the muscle to allow slow diffusion.
-drug needs to be oil soluble.

Question 24

Why is inhalation of drugs more effective than per oral administration?

Answer 24

because with inhalation, less of the drug amount is subject to degradation by digestive enzymes and have the ability to get to the brain very quickly.

Question 25

Difference between inhalation of gass and smoke (solids)

Answer 25

smoke particles and ask will not revaporize after it is dissolved in the lbood and therefore cannot be exhaled or eliminated via the respiratory system. smokes will thus collect in the lungs.

Question 26

In intranasal administraition, drugs are sniffed into nostrils and absorbed via _____membranes

Answer 26

mucus membranes.

Question 27

In oral administration, drugs are absorbed along GI tract, but the portion that does the absorbing in the mouth are the _____ membranes

Answer 27

buccal

Question 28

Blood is collected from the blood vessels around the GI tract and delivered to the liver via the _____

Answer 28

hepatic portal system

Question 29

Are ions and polar molecules lipid soluble?

Answer 29

no, they can therefore not cross the ion membrane without channels.

Question 30

Percentage of drug ionization is dependent by:

Answer 30

mainly PKA ; the pH at which half its molecules are ionized

Question 31

would a drug that is fully ionized in the digestive system be effective/

Answer 31

No, it won’t cross the membranes.

Question 32

Ideal drug in reference to PKAs:

Answer 32

Bases with lower pKAs and acids with higher pKAs

Question 33

Transdermal administration

Answer 33

absorbed through the skin

Question 34

T/F A drug that is soluble in water would be effectively administered in transdermal administration

Answer 34

false. The skin is water resistant, it would be best if the drug was very lipid soluble.

Question 35

Main factors affecting Drug distribution

Answer 35

1) Lipid Solubility; lipid soluble drugs will be easily absorbed but may get stored in the body fat and thus will take a long time to disperse
2) Ion trapping: injection of a non-lipid soluble drug (pka dependent) may make the drug slow to absorb
3) Blood Brain Barrier
4) Active and Passive transport
5) Protein Binding: drug may bind to large molecule that cannot fit through pore, limits distributions.
6) Placental barrier

Question 36

What is the main part of the medulla that is not covered by the blood brain barrier? Why?

Answer 36

area postrema of medulla not covered by blood brain barrier because it triggers vomiting

Question 37

Why is urine typically acidic?

Answer 37

because the kidneys mainly absorb things that are lipid soluble (they pass through the cell membrane) and selectively absorb ions via active and passive transports.

Acids are typically not reabsorbed into the blood because they are ionic, they tend to be retained in the urine.

Question 38

Half life applies to a drug that has _____ Kinetics

Answer 38

first order

Question 39

what is an example of a drug that does not follow a half-life curve

Answer 39

alcohol– it follows zero order kinetics.

Question 40

Enzyme induction

Answer 40

levels of the enzyme go up in the body, usually because of a specific drug that uses that enzyme.

Question 41

Example of enzyme induction

Answer 41

elevated levels of alcohol dehydrogenase in heavy drinkers.

Question 42

What does Disulfiram do?

Answer 42

blocks ALDEHYDE dehydrogenase and prevents the breakdown of aldehyde into acetylcoA–> causes sickness

Question 43

What does grapefruit juice to cytochrome enzyme?

Answer 43

affects FIRST PASS METABOLISM, and results in higher blood levels of many drugs.