Chapter 5: Pharmacodynamics (Week 2)

Question 1

Pharmacodynamics

Answer 1

The study of the biochemical and physiologic effects of drugs on the body and the molecular mechanisms by which those effects use produced

The study of what drugs do to the body and how they do it

Question 2

Dose-response relationship

Answer 2

The relationship between the size of can administered dose and the intensity of the response produced

Question 3

Dose-response relationships determine…

Answer 3

1. Minimum amount of drug needed to elicit a response
2. Maximum response a drug can elicit
3. How much to increase the dosage to produce the defined increase in response

Question 4

Basic feature of the dose-response relationship

Answer 4

As dosage increases, the response becomes progressively larger

Question 5

3 phases of doge-response relationship

Answer 5

1. Doses too low to elicit a measurable response
2. Increase in dose elicits a corresponding increase in the response
3. Increase in dose is unable to elicit a further increase in response

Question 6

2characteristic properties of drugs

Answer 6

Maximal efficiency & relative potency

Question 7

Maximal efficacy

Answer 7

The larger effect that A drug can produce

Indicated by the height of the dose-response curve

Question 8

Relative potency

Answer 8

The amount of drug we must give to elicit an effect

Indicated by the relative position of the dose-response curve along the x axis (how soon it rises)

Question 9

Receptor

Answer 9

Any functional macromolecule in a cell to which a drug binds to produce its effects

Question 10

Drug receptor interactions equation

Answer 10

D + R = D-R Complex -> Response

Question 11

How is receptor activity regulated?

Answer 11

Endogenous compounds (neurotransmitters, hormones, other regulatory molecules)

Question 12

What happens when a drug birds to a receptor?

Answer 12

1. Mimic or block the actions of endogenous regulatory molecules
2. Increase or decrease rate of physiologic activity normally controlled by that receptor

Question 13

4 primary receptor families

Answer 13

1. Cell membrane-embedded enzymes
2. Ligand-gated ion channels
3. G protein-coupled receptor systems
4. Transcription factors

Question 14

Ligand-binding domain

Answer 14

Specific region of the receptor where binding of drugs and endogenous regulatory molecules takes place

Question 15

Agonist drug

Answer 15

One that mimics the action of the endogenous regulatory molecule

Question 16

2 theories of drug-receptor interaction

Answer 16

1. Simple occupancy theory
2. Modified occupancy theory

Question 17

Simple occupancy theory

Answer 17

1. The intensity of the response to a drug is proportional to the number of receptors occupied by drug that and that
2. a maximal response will occur when all receptors have been occupied

Question 18

Modified occupancy theory

Answer 18

All drugs acting at a particular receptor are identical with respect to (1) the ability to bind to the receptor and (2) the ability to influence receptor function once binding has taken place

Question 19

Modified occupancy theory ascribes what 2 qualities to drugs

Answer 19

Affinity and intrinsic activity

Question 20

Affinity

Answer 20

Strength of attraction between a drug and it’s receptor

Question 21

Intrinsic activity

Answer 21

Ability of a drug to activate the receptor

Question 22

Agonists

Answer 22

Drugs that mimic the body’s own regulatory molecules
Molecules that activate receptors

Has affinity & high intrinsic activity

Question 23

Antagonists

Answer 23

Drugs that block the actions of endogenous regulators
Produce effects by preventing receptor activation by endogenous regulatory molecules and drugs

Affinity but no intrinsic activity

Question 24

Partial agonists

Answer 24

Mimic actions of endogenous regulatory molecules, but produce responses of intermediate intensity

Only has moderate intrinsic activity

Can act as antagonists or agonists

Question 25

Noncompetitive (insurmoontable) antagonists

Answer 25

Bind irreversibly to receptors

Reduce number of receptors available for activations

Reduce maximal response an agonist can elicit

Question 26

Competitive (surmountable) antagonists

Answer 26

Bind reversible to receptors

Compete with agonists for receptor binding

Question 27

ED 50

Answer 27

Dose @ middle of frequency distribution curve

( average effective close)

Dose that is required to produced defined therapeutic response in 50% of the population

Question 28

Therapeutic index

Answer 28

Measure sure of a drug’s safety

Ratio of drug’s LD50 to its ED50

Question 29

LD 50

Answer 29

Average lethal dose

Dose that is lethal to 50% of the animals treated

Question 30

Adverse drug reaction

Answer 30

Any noxious, unintended, undefined effect that occurs at normal drug doses

Question 31

Patients at increased risk of adverse dog effects

Answer 31

Very young, older adults, very ill, taking multiple medications

Question 32

How does grapefruit juice affect drug abgorptio?

Answer 32

Inhibits intestinal metabolism, inverse absorption, increase blood level

Question 33

Iatrogenic disease

Answer 33

Disease that occurs as due result of medical care or treatment

Question 34

Idiosyncratic effect

Answer 34

Adverse drug reaction based on a genetic predisposition

Question 35

Paradoxical effect

Answer 35

Opposite of intended drug effect

Question 36

Carcinogenic effect

Answer 36

Drug-induced cancer

Question 37

Teratogenic effect

Answer 37

Drug-induced birth defect

Question 38

Most common large of acute liver failure

Answer 38

Drugs

Question 39

Tornadoes de pointes

Answer 39

Dysrhythmia that can progress to fatal ventricular fibrillation

Question 40

Bioavailabily

Answer 40

Amount of active drug that reaches the systemic circulation from its site of administration

Question 41

Pregnancy risk categories

Answer 41

A: remote risk of fetal harm
B: slightly more risk than A
C: greater risk than B
D: proven risk of fetal harm
X: proven risk of fetal harm

Question 42

How do children ages 1 to 12 years differ pharmacokinetically from adults?

Answer 42

Metabolize drugs faster