Worksheetsprinciples of drug action p.2
Total questions: 46
Worksheet time: 27mins
Drug A and Drug B have the same efficacy at the M3 muscarinic receptor; however, Drug A is more potent than Drug B.
If Drug A is a full agonist, what can you deduce about Drug
B?
a) Drug B is a competitive antagonist of Drug A
b) Drug B is also a full agonist
c) Drug B is a partial agonist
d) Drug B is a physiological antagonist of Drug A
Which of the following statements regarding agonists is incorrect?
a) An agonist with high affinity will always trigger a strong response
b) A partial agonist will have an intrinsic efficacy between 0 and 1
c) An agonist acting on the central nervous system can produce an overall
inhibitory response to the central nervous system
d) An agonist will bind to a receptor and activates its function
Pharmacodynamics describes:
the effects of the drug on the body
the effects of the body on the drug
(adme)
the study of genetic influences on responses to drugs, associated with adverse drug reactions (ADRs) within a gene population
the study of drug effects at the population level
the cost effectiveness of using individual or classes of drug
Pharmacokinetics describes:
the effects of the drug on the body
the effects of the body on the drug
(adme)
the study of genetic influences on responses to drugs, associated with adverse drug reactions (ADRs) within a gene population
the study of drug effects at the population level
the cost effectiveness of using individual or classes of drug
Pharmacogenomics describes:
the effects of the drug on the body
the effects of the body on the drug
(adme)
the study of genetic influences on responses to drugs, associated with adverse drug reactions (ADRs) within a gene population
the study of drug effects at the population level
the cost effectiveness of using individual or classes of drug
example of pharmacogenomics:
defects in the gene for the P450 enzyme CYP2D6 cause poor metabolism of the anti-depressant fluoxetine (Prozac) and has led to deaths
withdrawal of the anti-arthritic drug rofecoxib (Vioxx) due to increased risk of heart attack/stroke
use of herceptin for breast cancer
Pharmacoepidemiology describes:
the effects of the drug on the body
the effects of the body on the drug
(adme)
the study of genetic influences on responses to drugs, associated with adverse drug reactions (ADRs) within a gene population
the study of drug effects at the population level
the cost effectiveness of using individual or classes of drug
example of pharmacoepidemiology
defects in the gene for the P450 enzyme CYP2D6 cause poor metabolism of the anti-depressant fluoxetine (Prozac) and has led to deaths
withdrawal of the anti-arthritic drug rofecoxib (Vioxx) due to increased risk of heart attack/stroke
use of herceptin for breast cancer
example of pharmacoeconomics
defects in the gene for the P450 enzyme CYP2D6 cause poor metabolism of the anti-depressant fluoxetine (Prozac) and has led to deaths
withdrawal of the anti-arthritic drug rofecoxib (Vioxx) due to increased risk of heart attack/stroke
use of herceptin for breast cancer
the definition of a drug
An exogenous biologically active compound taken with the intent to produce a change in the body. This effect may be positive but can be negative.
A chemical preparation which usually contains one or more drugs administered
with the purpose of producing a positive therapeutic effect.
the definition of medicine
An exogenous biologically active compound taken with the intent to produce a change in the body. This effect may be positive but can be negative.
A chemical preparation which usually contains one or more drugs administered
with the purpose of producing a positive therapeutic effect.
which of these is an example of a drug?
Cannabidiol (CBD)
Epidyolex
which of these is an example of a medicine
Cannabidiol (CBD)
Epidyolex
who proposed the magic bullet theory whereby a drug would have selectively toxicity e.g. therapy without toxicity.
Paul Ehrlich
John Newport Langley
Brian McCain
John Ronald
described drug action (nicotinic acting at the neuromuscular junction) in terms of interaction with a “receptive substance”.
Paul Ehrlich
John Newport Langley
Brian McCain
John Ronald
who tested receptor action by effects of nicotine and curare on skeletal muscle contraction
Paul Ehrlich
John Newport Langley
Brian McCain
John Ronald
salbutomal works on which extra-cellular receptor to dilate the bronchioles (airways)
b1-adrenoceptor
b2-adrenoceptor
to be able to set up the right test you have to ensure that you measure the
access
response
duration
side effects
concentration
in vitro assays describe
•performed or taking place in a test tube, culture dish, or elsewhere outside a living organism.
performed or taking place in a living organism.
in vivo assays describe
•performed or taking place in a test tube, culture dish, or elsewhere outside a living organism.
performed or taking place in a living organism.
examples of in vivo test
Intervention (e.g. drug x)
Genetic modification
(e.g. KO of Gene Y)
drug X on an isolated rodent heart preparation
human stem cells
drug X in a cellular model of depression
why can isolating one process be challenging given the array of targets involved and give an example
Several different targets to modulate.
All can impact on contractility.
Model systems cannot replicate the same common pathways
smooth muscle contractility.
the effect of salbumatol on the bronchioles
the measure contractility you can monitor intracellular (a) levels via fluorescence.
if a drug has a low therapeutic index it means
only need a small increase in dose to produce toxic effects
the safer the drug
ratio of toxic to therapeutic dose.
IC50 can also be used be referred as
agonist potency
antagonist potency
efficacy
EC50
properties of a drug
•Drugs must dissolve in H2O
less than 500
Electronegativity is a measure of an atoms ability to ....... electrons towards itself
attract
repel
from the left to the right of the periodic table electronegativity
increases
decreases
going down the periodic table electronegativity
increases
decreases
what is the most electronegative element
F
O
Cl
Na
Hydrogen bonding describes
Interaction between electron-rich atom (Hydrogen Bond Acceptor, HBA) and electron deficient hydrogen atom (Hydrogen Bond Donor, HBD).
Ionic interaction between groups carrying opposite charges.
an attractive interaction between atoms which results from induced dipoles, and a repulsive interaction, which results from overlap of the electron clouds of two atoms when they get too close
Electrostatic interactions describes
Interaction between electron-rich atom (Hydrogen Bond Acceptor, HBA) and electron deficient hydrogen atom (Hydrogen Bond Donor, HBD).
Ionic interaction between groups carrying opposite charges.
an attractive interaction between atoms which results from induced dipoles, and a repulsive interaction, which results from overlap of the electron clouds of two atoms when they get too close
Van der waals interactions describes
Interaction between electron-rich atom (Hydrogen Bond Acceptor, HBA) and electron deficient hydrogen atom (Hydrogen Bond Donor, HBD).
Ionic interaction between groups carrying opposite charges.
an attractive interaction between atoms which results from induced dipoles, and a repulsive interaction, which results from overlap of the electron clouds of two atoms when they get too close
Isomer : Different compounds which have the same
molecular formula
empirical formula
no. electrons
enatomers
WHY ARE ENANTIOMERS IMPORTANT?
select the reasons why adrenaline was not suitable for the treatment of asthma
it has a short duration of action
it has a long duration of action
no selectivity for b2-receptors
no selectivity for b1-receptors
leading to side effects, particularly cardiovascular effects.
adrenaline was replaced by which antiasthmatic agent.
isoprenaline
salbumatol
noremphoxine
fluticasone
isoetharine was shown to be selective for b2-receptors ( because of of its bulky N-alkyl substituent) but why were the effects short lasting?
a result of the drugs being taken up by tissues and methylated by the metabolic enzyme catechol-O-methyltransferase (COMT), to form an inactive ether.
However it showed no selectivity between the different types of b-receptors
what made salbutamol have an affinity for only the b-receptors?
Increasing the size of the group on nitrogen
forming an inactive ether.
-COOH
basic
acidic
-NH2
acidic
basic
the definition of formation
An exogenous biologically active compound taken with the intent to produce a change in the body. This effect may be positive but can be negative.
A chemical preparation which usually contains one or more drugs administered
with the purpose of producing a positive therapeutic effect.
the process in which different chemical substances, including the active drug, are combined to produce a final medicine.
LOW P VALUE IS
A
B
C
Dissolve in both
A
B
C
High LogP value
A
B
C
plasma concentration
volume of distribution dose
volume of distribtuion dose x kg
waterconcentration of drug
