Pharm 2060B Module 7

Front 1

In DRC, an increase in the drug dose increases the responses. What word can be used to describe this?

Back 1

monotonic

Front 2

What is the shape of dose response curves?

a) logarithmic

b) linear

c) exponential

d) semi-logarithmic

Back 2

d. They are semi-logarithmic

Front 3

What are the three phases of the semi-log DRC?

Back 3

Phase 1: The dose is too low to elicit a response

Phase 2: The dose is high enough such that the response is graded and linear

Phase 3: Increased doses do not lead to greater responses. Drug toxicity may incur with increased doses.

Front 4

Define efficacy

Back 4

a measure of how effective a drug is at a given dose (x axis constant)

Front 5

Define maximal efficacy

Back 5

The maximum effect (responses) a drug is capable of achieving

Front 6

When comparing two drugs for maximal efficacy, what parameter on the graph are we looking at?

Back 6

Their relative heights

Front 7

What does it mean to titrate the dose of a drug?

Back 7

Doctors start with a low dose of the drug, and slowly increase the dose of the drug while monitoring the patient's response

Front 8

Define potentcy

Back 8

the amount of drug required to elicit a pharmacological response (y axis constant0

Front 9

T/F high potency means more therapeutically effective.

Back 9

False.

Front 10

What must be true in order to compare drugs for their relative potencies

Back 10

They must produce the same pharmacological effect

Front 11

Define ED50

Back 11

Amount of dose required to produce an effect in 50% of respondents

Front 12

Most drugs act on _________

Back 12

cellular macromolecules

Front 13

majority of drug targets are receptors but drugs also act on what three things?

Back 13

enzymes, ion channels, transport proteins

Front 14

t/f drugs typically mimic exogenous compounds in the body

Back 14

false. they typically mimic endogenous compounds in da body

Front 15

name a drug that does not act on a cellular target

Back 15

antacids

Front 16

describe the drug and the mechanism of action for antacid

Back 16

antacid is a drug used to provide symptomatic relief for certain GI disorders. it is simply a base that neutralizes the stomach acid

Front 17

Define receptor

Back 17

a protein that a drug binds to that produces a measurable response

Front 18

the majority of receptors are proteins that are able to translate __________ _________ into

___________ __________

Back 18

the majority of receptors are proteins that are able to translate extracellular signals into biological responses

Front 19

name the 4 most important receptor types

Back 19

1. ligand gated ion channels

2. g-protein couples receptors

3. enzyme linked receptors

4. intracellular receptors/transcription factors

Front 20

Describe the function of ligand gated ion channels

Back 20

Ions cannot directly penetrate the cell membrane, they require ion channels. Certain ligands (i.e. drugs or endogenous molecules) can cause the control of the opening and closing of ion channels. The ligand, once bound to the receptor on the gated ion channel, opens the channel and allows ions to pass into the cell, producing an instantaneous change in function.

Front 21

How does GABA function to cause sedation and relaxation.

Back 21

The GABA neurotransmitter (ligand) binds to receptors on the ligand gated ion channels and elicits an influx of chloride.

Front 22

What drug class have a similar mechanism of action akin to that of GABA

Back 22

Benzodiazepines

Front 23

50% of marketed drugs mediate their effects through which receptor?

Back 23

G-protein coupled receptors (GPCRs)

Front 24

Name and describe the 3 components of GPCRs

Back 24

1. a 7 transmembrane spanning protein receptor, with a ligand binding domain

2. a 3 subunit G-protein

3. an effector molecule (such as an enzyme)

Front 25

describe the mechanism of action of GPCRs

Back 25

a ligand binds to the ligand binding domain on the 7 transmembrane protein receptor. this causes the G-protein to dissassociate from the receptor and bind to and activate the effector molecule, which produces an intracellular response.

Front 26

Name 3 endogenous neutrotransmitters that mediate their effects by binding to GPCRs

Back 26

norepinephrine, serotonin, histamine

Front 27

describe the structure of enzyme linked receptors

Back 27

they span the entire cell membrane. they have a ligand binding domain on the outside of the cell, and an enzymatic catalytic site on the inside of the cell.

Front 28

Describe the mechanism of action of enzyme linked receptors with reference to insulin.

Back 28

Binding of insulin to the ligand binding domain on the outside of the cell causes enzyme-mediated (inside of cell) phosphorylation and activation of an intracellular effector molecule. This effector molecule causes an increase in the translocation of glucose transporters to the cell membrane, effectively leading to greater uptake of glucose.

Front 29

how do ligands access transcription factors

Back 29

They must either directly penetrate the PM or become uptaken by a uptake transport protein

Front 30

describe the function of intracellular receptors

Back 30

binding of a ligand to an intracellular receptor causes translocation of this complex to the nucleus and the binding to DNA. Binding to DNA initiates transcription of mRNA.

Front 31

What are 2 differences between transcription factors and the other 3 receptors?

Back 31

1. Transcription factors are receptors that are intracellular

2. Transcription factors take hours-days to see the ultimate effects of the ligand binding occuring

Front 32

What is an important chemical property of ligands that bind to trans factors? Name 2 examples of these ligands.

Back 32

They must be super lipophilic. Testosterone and Estrogen.

Front 33

what is a selective drug?

Back 33

a drug that will only bind to one receptor.

Front 34

why is it that selective drugs may still have side effects?

Back 34

because even through the drug may bind to only one receptor, if the target center for therapy is in the brain, but the receptor is located in the brain and the intestine, then the drug will produce side effects in the intestine as well.