Pharmacodynamics - Mechanism of drug action

Question 1

what two factors determine how quickly a drug initiates an effect and how long the effect lasts

Answer 1

strength and length

Question 2

penicillin binds to what enzyme on bacterial cell wall to prevent cross linking

Answer 2

transpeptidase
this means if the bacterial load is high a higher dose of penicillin must be given to completely eliminate the bacteria from the body

Question 3

factors that can affect the pharmacodynamics of a drug include

Answer 3

change in receptor binding
alteration in level of binding protein
decrease receptor sensitivity
genetic mutation
selectivity
malnutrition
aging
effects of other drugs

Question 4

All drugs only alter the pace of ongoing activity and do not impart new functions on any system or organ
T or F

Answer 4

F
the only exception to this rule is gene based drugs

Question 5

stimulation and depression is applied to specialized cells while irritation is applied to non specialized cells and is non selective
T or F

Answer 5

T

Question 6

activated charcoal binds with poisons in stomach is an example of what mechanism of drug action

Answer 6

physical mechanism
in physical mechanism there is no change to cells in the body and the drug effect is strictly physical
other examples include
mannitol as an osmotic diuretic
bulk laxatives e.g ispaghula

Question 7

example of chemical mechanism of drug action include

Answer 7

antacids e.g NaHCO3
acetylcholineesterase reactivator e.g pralidoxime
cholestyramine for bile and cholesterol sequestration
Chelating agents e.g dimecaprol, penicilamine, desferroxiamine

Question 8

angiotensin converting enzyme inhibitors use what kind of inhibition

Answer 8

e.g captopril
competitive inhibition

Question 9

reversible cholinesterase e.g neostigmine
and xanthine oxidase inhibitor e.g allopurinol
are all examples of competitive inhibitors
T or F

Answer 9

T

Question 10

the action of allopurinol on xanthine oxidase enzyme is what kind of antagonism

Answer 10

competitive inhibition

Question 11

the effect of aspirin on cyclooxygenase is what kind of inhibition

Answer 11

non competitive inhibition

Question 12

omeprazole deactivates proton pump in stomach via what mechanism

Answer 12

non competitive inhibition

Question 13

irreversible anticholinesterase like organophosphate and insecticide act via what mechanism

Answer 13

non competitive inhibition

Question 14

monamine oxidase inhibitors e.g imipramine act via what mechanism

Answer 14

non competitive inhibition

Question 15

list 2 examples each of channel blockers of these ions
1. Na
2. K
3. Ca
4. Cl

Answer 15

1. Procainamide, quinidine, local anesthetic (
2. Amiodarone, sulfonylurea
3. nifedipine, verapamil, diltiazem
4. benzodiazepens

Question 16

list 2 uses each of channel blockers of these ions
1. Na
2. K
3. Ca
4. Cl

Answer 16

1. Arrhythmia and anesthetic
2. Arrhythmia(blockage causes prolonged refractory period)
3. Arrhythmia and hypertension
4. the slide explanation just dey somehow man
   if you see it in incourse skip it

Question 17

list the inhibitors of these carriers
1.noradrenaline vessicular uptake
2.neuronal reuptake of noradrenaline
3.neuronal reuptake of serotonin
4.weak acid(e.g uric acid) carriers

Answer 17

1.reserpine
2.desipramine
3.fluoxetin
4.probenecid (thus prevents uric acid reabsorption and facilitate excretion)

Question 18

The specific chemical constituent of the cell with which drugs interact with to produce it’s pharmacological effect is the

Answer 18

Receptor

Question 19

drug receptors are regulatory micromolecules
T or F

Answer 19

F
macromolecules

Question 20

list the 4 characteristics of receptors

Answer 20

The 4 S
sensitivity
specificity
selectivity
saturability

Question 21

list 4 molecules that can serve as a receptor

Answer 21

Enzymes
membrane proteins
nucleic acid
complex polysaccharides

Question 22

an agent which activates a receptor to produce submaximal effect but antagonizes the agonist is called

Answer 22

a partial agonist

Question 23

an agent which activates a receptor to produce an effect opposite to that of an agonist is called

Answer 23

inverse agonist
e.g Beta Carboline

Question 24

the capacity to induce functional changes in the receptor in a way that produces an effect is called

Answer 24

Intrinsic activity / efficacy

Question 25

irreversible anticholinesterase e.g organophosphates form what kind of bond

Answer 25

covalent bond

Question 26

most drugs employ what kind of bond to receptors

Answer 26

ionic bond

Question 27

a receptor would produce a response only when it is occupied by an appropriate ligand with the response directly proportional to the fraction of occupied receptors This theory is called

Answer 27

Occupancy Theory this means maximal respones will only occur when all the receptors are occupied

Question 28

response is proportional to rate of onset and offset of drug binding to receptor response is proportional to rate of drug-receptor Complex dissociation The above statement describes what Receptor theory

Answer 28

Rate theory

Question 29

according to rate theory ______ determines whether a ligand is an agonist, antagonist or partial agonist

Answer 29

the duration of drug-receptor Complex dissociation

Question 30

response is directly proportional to intrinsic activity and fraction of occupied receptors the receptor theory above is called

Answer 30

Stephenson Theory

Question 31

Response is a function of affinity, maximum response can be produced without 100% occupancy

Answer 31

Ariens theory

Question 32

binding of ligand to receptor is based on plastic modeling with receptor and ligand both undergoing a dynamic process with agonist inducing conformational change in the receptor the receptor theory above is the

Answer 32

induced fit theory

Question 33

when a drug receptor interaction occurs either a specific conformational pertubation(by agonist) which leads to a biological response or a nonspecific conformational pertubation(by antagonist) which leads to no response This receptor theory is called

Answer 33

Macromolecular conformational theory

Question 34

List 6 the receptor theory

Answer 34

1. Occupancy theory 2. Rate theory 3. Stephenson theory 4. Ariens theory 5. Induced fit theory 6. Macromolecule Pertubation theory

Question 35

Receptors have 2 domain which are

Answer 35

Ligand binding domain Effector domain it is the effector domain that undergoes conformational change

Question 36

the basis for designating receptor subtypes is the

Answer 36

relative tissue distribution of receptor

Question 37

receptor subtypes such as serotonin(5-HT) where delineated from each other based ____

Answer 37

high affinity and displacement by various selective agonist/antagonist

Question 38

receptors without a known ligand are called

Answer 38

orphan receptors

Question 39

receptors/site which binds specific drugs without eliciting a pharmacological response are known as

Answer 39

Silent receptors/Drug acceptors/ Site of loss e.g plasma proteins

Question 40

the remaining unoccupied receptors in a tissue are called

Answer 40

spare receptors

Question 41

in upregulation there is increase in number of receptors with subsequent increase in sensitivity T or F

Answer 41

T

Question 42

list 2 disease in which there is mutations of genes encoding for G protein coupled receptors

Answer 42

Cancer Hypoparathyroidism

Question 43

list the 4 major categories of transducer mechanism

Answer 43

GPCR receptors with intrinsic ion channels receptors linked with enzymes transcription factors(receptors for gene expression)

Question 44

GPC-receptor have how many transmembrane domain

Answer 44

7

Question 45

GPCR have ___ alpha helical membrane spanning hydrophobic amino acid segments

Answer 45

7

Question 46

gpcr have how many loops

Answer 46

3 intracellular and 3 extracellular 6

Question 47

ligand gated ion channels open very fast and are thus confined to excitable tissue T or F

Answer 47

T

Question 48

G proteins have how many sub units

Answer 48

3 Ga GB GY

Question 49

G proteins are classified into Gi, Gs and Gq based on

Answer 49

their Ga subunit

Question 50

list the functions of these G proteins 1.Gi 2.Gs 3.Gq 4.Go

Answer 50

1.inhibits adenyl cyclase 2.stimulate adenyl cyclase 3.stimulates phospholipase C 4.inhibits calcium channel there's a G12/13 which regulates actin cytoskeletal modeling in migrating cells or cancer cells metastatic

Question 51

list the 3 second messenger system

Answer 51

CAMP CGMP Calcium and phosphoinositol system

Question 52

in their inactive form G proteins are bound to

Answer 52

GDP

Question 53

the G protein is bound to the receptor in its active state T or F

Answer 53

F in its inactive state when it the receptor is stimulated it activates the G protein which subsequently detaches from the receptor this detachment allows the receptor to bind more inactive G proteins and activate them

Question 54

what are the 3 possible targets for G proteins

Answer 54

adenyl cyclase (for CAMP formation) phospholipase c (for Ip3 and DAG formation) ion channels (particularly Ca and K)

Question 55

the GBY dimer formed (when the G protein is activated and split) function in

Answer 55

modulation of signal