Ch 4 Pharmacokinetics / Dynamics

Question 1

The study of drug movement through the body

Answer 1

Pharmacokinetics

Question 2

Name the four Basic processes of pharmacokinetics

Answer 2

Absorption

distribution

metabolism

excretion

Question 3

The drugs movement from the site of administration into the blood

Answer 3

Absorption

Question 4

The movement of the drug from the blood to the interstitial space of tissues and from there into the cells

Answer 4

Distribution

Question 5

The enzymatically mediated alteration of drug structure. This is also known as biotransformation

Answer 5

Metabolism

Question 6

The movement of drugs and their metabolites out of the body

Answer 6

Excretion

Question 7

True or false: the combination of metabolism and excretion is called elimination

Answer 7

True

Question 8

The goal of applying knowledge of pharmacokinetics to drug therapy is to maximize beneficial effects and minimize harm

Answer 8

True

Question 9

True or false: distribution is the only phase of pharmacokinetics that involves drug movement across membranes

Answer 9

False: To move through the body in all four phases of pharmacokinetics drugs must cross membranes

Question 10

Name the three ways drugs can cross cell membranes

Answer 10

Channels or pores

passage with the aid of a transport system

direct penetration of the membrane (most common)

Question 11

True or false: membranes are composed primarily of lipids therefore to directly penetrate a membrane - a drug must be lipid soluble.

Answer 11

True

Question 12

True or False: potassium and sodium are too large to cross membranes through channels or pores

Answer 12

False: K+ and Na+ are examples of the smallest of compounds that can pass through these channels if the channel is the right one.

Question 13

Name two kinds of molecules that are not lipid soluble and cannot penetrate membranes

Answer 13

Polar molecules

ions

Question 14

True or false: water is an example of an ion with a positive charge

Answer 14

False: water is an example of a polar molecule that has no net charge

Question 15

True or False: Ions are an example of molecules that have a net positive charge

Answer 15

False: ions are molecules that have a net electrical charge that can be either positive or negative

Question 16

___________ Is the process whereby a drug accumulates on the side of a membrane where the pH most favors it’s ionization

Answer 16

Ion trapping

Question 17

Acidic drugs accumulate on the ___________ side

Answer 17

Alkaline

Question 18

Basic drugs accumulate on the __________ side

Answer 18

Acidic

Question 19

What five factors affect drug absorption

Answer 19

Rate of dissolution

surface area

blood flow

lipid solubility

PH partitioning

Question 20

True or false: the rate of absorption determines how soon effects will begin where is the amount of absorption helps determine how intense effects will be

Answer 20

True

Question 21

True or false: drug preparations are considered chemically equivalent if the drug they contain is absorbed at the same rate in to the same extent

Answer 21

False: Drug preparations are considered chemically equivalent if they contain the same amount of the identical chemical compound / drug

Preparations are considered equal in bio availability if the drug they contain is absorbed at the same rate in to the same extent

Question 22

What three processes affect drug distribution ?

Answer 22

Blood flow to the tissues,

the ability of a drug to exit the vascular system,

the ability of a drug to enter cells

Question 23

Why must abscesses usually be surgically drained for drug therapy to be effective?

Answer 23

Abscesses have no internal blood vessels so they have no blood supply therefore antibiotics cannot reach the bacteria within

Question 24

___________ Is a transporter known as a multi drug transporter protein that transports a wide variety of drugs out of cells

Answer 24

P - glycoproteins (PGP)

Question 25

Most drug metabolism takes place in the _________

Answer 25

Liver

Question 26

What is another name for the hepatic microsomal enzyme system that takes place in the liver?

Answer 26

P450 or cytochrome P450 which is made of 12 closely related enzyme families

Question 27

Name the three P450 families that metabolize drugs

Answer 27

CYP1 CYP2 CYP3

Question 28

The other 9 P450 enzyme families metabolize __________ compounds like ______ &________.

Answer 28

Endogenous Steroids and fatty acids

Question 29

What is the most important consequence of drug metabolism and why

Answer 29

Promotion of renal drug excretion is the most important consequence because the kidneys are the major organ of drug excretion. They cannot excrete drugs that are highly lipid soluble. If drugs can be converted into more hydrophilic forms metabolic conversion can accelerate renal excretion of many agents

Question 30

Name six consequences of drug metabolism of therapeutic significance

Answer 30

Accelerated renal excretion of drugs, drug and activation, increased therapeutic action, activation of pro drugs, increased toxicity, decreased toxicity

Question 31

Metabolism converting codeine and some morphine is an example of what

Answer 31

Increased therapeutic action

Question 32

This is a compound that is pharmacologically an active as administered and undergoes conversion to it’s active form through metabolism

Answer 32

Prodrug

Question 33

This refers to the rapid hepatic an activation of certain oral drugs

Answer 33

First pass effect

Question 34

This is the time required for the amount of drug in the body to decrease by 50% and determines dosing interval

Answer 34

Drug half life

Question 35

The study of the bio chemical and physiologic effects of drugs on the body and the molecular mechanisms by which those effects are produced

Answer 35

Pharmacodynamics

Question 36

The largest defect that he drug can produce

Answer 36

Maximal efficacy

Question 37

The amount of drug we must give to elicit an effect it’s indicated by the relative position of the dose response curve

Answer 37

Potency

Question 38

This is any functional macromolecule any cell to which a drug binds to produce it’s effects

Answer 38

Receptor

Question 39

This refers to the strength of the attraction between a drug and it’s receptor

Answer 39

Affinity Drugs with higher Affinity are very potent

Question 40

The ability of a drug to activate a receptor up on binding

Answer 40

Intrinsic activity Drugs with high intrinsic activity have high maximal efficacy

Question 41

True or false: agonist are molecules that deactivate receptors

Answer 41

FALSE Agonists - ACTIVATE

Question 42

True or false: antagonists produce their effects by preventing receptor activation by endogenous regulatory molecules and drugs

Answer 42

TRUE

Question 43

The average effective dose - this is also defined as the dose required to produce a defined therapeutic response in 50% of the population

Answer 43

ED50

Question 44

This is a measure of a drugs safety it is defined as the ratio of a drugs lethal dose (LD50) to its effective dose (ED50). The larger this is the safer the drug is

Answer 44

Therapeutic index

Question 45

When another substance alters a drug efficacy effects or safety

Answer 45

Drug interaction

Question 46

True or false: albuterol and propanolol should not be taken together

Answer 46

True : Propanolol reduce his albuterol therapeutic effects

Question 47

Which isoenzyme does grapefruit juice effect by inhibiting metabolism metabolism

Answer 47

CYP3A4

Question 48

Name some examples of food on drug

Answer 48

MAO inhibitor combined with foods rich in tyramine like aged cheeses yeast extract and she Chianti wine. This combination causes life-threatening elevation and blood pressure Theophylline combined with caffeine can cause excessive CNS excitation Potassium sparing diuretics like spironolactone plus salt substitute can result in dangerously high potassium levels Aluminum containing antacids plus citrus beverages can result in excessive absorption of aluminum

Question 49

How does vitamin K reduce the effects of warfarin?

Answer 49

Warfare and inhibits vitamin K dependent clotting factors so in vitamin K is more abundant warfarin and is less able to inhibit the clotting factors and therapeutic effects decline