intro to pharmacology

Question 1

what is pharmacology?

Answer 1

the study of substances that interact with living systems through chemical processes

Question 2

define drug

Answer 2

any substance that interacts with a molecule or protein that plays a regulatory role in living systems

Question 3

define endogenous drugs

Answer 3

drugs originating inside the body, including hormones

Question 4

define poisons

Answer 4

drugs that almost exclusively have harmful effects

Question 5

why are all drugs poisons?

Answer 5

because all drugs have adverse effects

Question 6

what are toxins?

Answer 6

poisons of biological origin, usually synthesised by plants or animals

Question 7

define receptor

Answer 7

a specific molecule (usually a protein) that interacts with a specific chemical, causing a change in the receptor that produces a regulated function

Question 8

name the types of receptors

Answer 8

ion channels
g-protein coupled receptor
RTKs
intracellular hormone receptors (nuclear receptor)

Question 9

what is the largest category of receptor?

Answer 9

GCPRs

Question 10

what is an agonist

Answer 10

any drug that binds to a receptor and activates it

Question 11

name the types of ion channels

Answer 11

ligand gated
voltage gated
2nd messenger regulated

Question 12

how does an agonist work?

Answer 12

mimics the natural ligand of the receptor. when the agonist leaves the receptor is usually deactivated and the effect stop

Question 13

give some examples of agonists that cause a covalent change in the receptor

Answer 13

aspirin - makes a covalent change in the receptor that keeps anti-platelet action on for the life of the platelet

Question 14

what is a partial agonist?

Answer 14

an agonist that binds to a receptor at the active site but is unable to cause maximal response even if all the receptors are occupied

Question 15

why are partial agonists useful?

Answer 15

its hard to give an overdose with them

Question 16

why do partial agonists have a smaller effect than full agonists?

Answer 16

they bind with a lower affinity for the receptor so they dont bind as strongly

Question 17

why does a partial agonist block the full agonist?

Answer 17

because they both bind to the same active site

Question 18

what is an inverse agonist?

Answer 18

an agonist that produces a response below the baseline response. it has an opposite effect to an agonist

Question 19

give an example of an inverse agonist and how it works

Answer 19

antihistamine - binds to a histamine receptor and stabilises it so it stops mast cells and basophils from releasing histamine granules and causing an immune response

Question 20

what is an antagonist?

Answer 20

any drug that binds to the receptor and prevents activation of the receptor

Question 21

define competitive antagonist

Answer 21

a drug that competes with the endogenous ligand for the the binding site. fits into active site and prevents activation of the receptor

Question 22

define non-competitive antagonist

Answer 22

a drug that binds to the receptor at a point that isn’t the binding site

Question 23

what is a chemical antagonist?

Answer 23

a chemical that binds directly to an agonist and prevents it from binding to a receptor

Question 24

what is a physiological antagonist?

Answer 24

when 2 substances have exactly opposite actions via different pathways

Question 25

what does ADME stand for?

Answer 25

absorption delivery metabolism elimination

Question 26

what is a strong acid?

Answer 26

an acid that dissociates completely into a negative ion and a proton

Question 27

what is a weak acid?

Answer 27

an acid that only partially dissociates

Question 28

which form of a drug is lipid soluble?

Answer 28

undissociated form | uncharged and protonated

Question 29

which form a drug is water soluble?

Answer 29

dissociated form

Question 30

what is the advantage of a drug being a weak acid/base?

Answer 30

it can switch between the dissociated and undissociated form so it can travel through different parts of the body

Question 31

in acidic solution, what form is a weak acid drug going to be in and why?

Answer 31

in the uncharged and undissociated form because the H+ ions in solution push the equilibrium to the left

Question 32

in alkali solution, what form is a weak acid drug going to be in and why?

Answer 32

charged and dissociated form because fewer H+ ions so equilibrium moves to the right

Question 33

when does pKa = pH?

Answer 33

when there is complete balance between the uncharged and charged form of the drug

Question 34

what is the range of pH of the body?

Answer 34

7.35-7.45

Question 35

what form is a weak acid drug generally going to be in the body and why?

Answer 35

charged and dissociated form because body pH is slightly alkaline so equilibrium shifts to the right to make more H+

Question 36

where is most of the protonated form of a drug found?

Answer 36

in the stomach

Question 37

what are drugs filtered by?

Answer 37

the glomerulus of the kidney

Question 38

what form of a drug will be reabsorbed back into the blood in a kidney?

Answer 38

a protonated, undissociated drug

Question 39

in what pH blood is a weak acid drug excreted fastest and why?

Answer 39

alkaline urine because more will be in the unprotonated form

Question 40

in what form will a drug be excreted?

Answer 40

dissociated form

Question 41

in what pH blood is a weak alkali drug excreted fastest?

Answer 41

acidic

Question 42

what is specificity?

Answer 42

which organ(s) a drug works on

Question 43

what is selectivity?

Answer 43

what receptor a drug binds to to produce an effect?

Question 44

define affinity

Answer 44

how tightly the drug binds to the receptor

Question 45

what bonds can a drug bind to a receptor with?

Answer 45

``` covalent ionic electrostatic lipophilic van der waals ```

Question 46

define pharmacokinetics

Answer 46

actions of the body on the drug

Question 47

define pharmacodynamics

Answer 47

actions of the drug on the body

Question 48

why is a logarithmic scale used?

Answer 48

easier to get dose reading on a logarithmic scale

Question 49

what is the maximal response?

Answer 49

the point where there is no further increase in response

Question 50

what does EC mean?

Answer 50

concentration

Question 51

what does ED mean?

Answer 51

dose

Question 52

what does EC50 mean?

Answer 52

the drug concentration at half the maximal response

Question 53

how can you tell a drug is a competitive antagonist from a graph of response against concentration?

Answer 53

need to add more of the drug to get a response. with enough of the agonist added, a maximal response can be achieved

Question 54

how can you tell a drug is a non-competitive antagonist from a graph of response against concentration?

Answer 54

maximal effect is reduced no matter how much agonist you bind, it cannot activate receptor at the same level bc the receptors its binded to cannot be used anymore.

Question 55

do all receptors have to be occupied to produce a response?

Answer 55

no

Question 56

how do spare receptors impact a tissue's response to a ligand?

Answer 56

increase sensitivity and speed of the response

Question 57

define efficacy

Answer 57

the maximal effect that a drug can produce regardless of dose

Question 58

define potency

Answer 58

the amount of drug that is needed to produce a given effect

Question 59

what determines potency?

Answer 59

affinity of a drug for a receptor and the number of receptors available

Question 60

which axis does the curve move in to show potency

Answer 60

horizontally

Question 61

which axis does the curve move to show efficacy?

Answer 61

vertical

Question 62

if a drug is more potent, which direction does the curve move in?

Answer 62

the right

Question 63

if a drug has a lower efficacy, which way does the curve move in?

Answer 63

down

Question 64

define intrinsic activity

Answer 64

the ability of a ligand to bind to receptors and activate them