Pharmacology

Question 1

What is an agonist?

Answer 1

a drug or molecule that binds to its receptor AND causes a downstream biological effect

Question 2

What is an antagonist?

Answer 2

a drug or molecule that binds to its receptor physically preventing another substance bind therefore preventing downstream effects indirectly

Question 3

What are ligand-gated ion channels?

Answer 3

transport that requires a ligand to bind thus allowing the transfer of ions through the membrane

Question 4

Give an example of g-protein coupled receptors?

Answer 4

adrenoreceptors

Question 5

what hormone binds to adrenoreceptors?

Answer 5

adrenaline

Question 6

adrenoreceptors are involved in the parasympathetic response, true or false

Answer 6

false, they are involved in the sympathetic response as they respond to adrenaline

Question 7

Give an example of a drug that uses kinase linked receptors?

Answer 7

insulin

Question 8

What is the role of alpha 1 and 2 adrenoreceptors upon stimulus by adrenaline?

Answer 8

1 - g protein couples with phospholipase C causing vasoconstriction

2 g protein blocks the activity of adenyl cyclase preventing ATP-generated cAMP and increasing potassium channels thereby relaxing the GI tract

Question 9

adrenoreceptor beta 1 causes dilation of the bronchi, true or false?

Answer 9

false, this is the role of adrenoreceptor 2

Question 10

How do beta adrenoreceptors illicit downstream effects?

Answer 10

upon binding of adrenaline to the receptor the g protein is activated and then binds to adenyl cyclase, this allows ATP to produce cAMP

Question 11

What are the physiological effects of beta 1 2 and 3 adrenoreceptor stimulation?

Answer 11

1 - increased heart rate and cardaic muscle contraction
2 - bronchial-dilation
3 - thermogenesis of skeltal muscle

Question 12

what is an example of a drug that is a beta 2 adrenoreceptor agonist?

Answer 12

salbutamol

Question 13

What partial agonists reduce heart rate and bind to beta-adrenoreceptors?

Answer 13

propanolol and pindolol

Question 14

What is a partial agonist?

Answer 14

a drug or molecule that exerts sub-maximal responses

Question 15

What is the EC50

Answer 15

the minimum plasma concentration required for the drug to be effective

Question 16

What is efficacy?

Answer 16

tendency of the drug to activate the receptor and result in a biological response

Question 17

What is affinity?

Answer 17

tendency of the drug to bind to its receptor successfully

Question 18

What drug compensates for the adrenoreceptor downregulation?

Answer 18

theophylline
also inhibits phosphodiesterase

Question 19

What are nuclear receptors?

Answer 19

protein monomers located in the nucleus of target cells and contain DNA binding domains

Question 20

What is Ka

Answer 20

dissociation equilibrium constant

Question 21

what is the dissociation equilibrium constant (Ka)?

Answer 21

the concentration at which the ligand occupies 50% of the receptors

Question 22

Give an example of an antidepressant that is a antagonist?

Answer 22

amitryptiline

Question 23

What drug is a calcium channel blocker and important for hypertension?

Answer 23

amlodipine

Question 24

What enzymes does ibuprofen block

Answer 24

Cox1 and Cox2

Question 25

What is the mechanism of amlodipine?

Answer 25

calcium channel blockers used for hypertension

Question 26

Which beta receptor does propranolol primarily target and which is the secondary target?

Answer 26

primary - beta 1 adrenoreceptor secondary - beta 2 adrenoreceptor

Question 27

propranolol is an agonist, true or false?

Answer 27

false it is an antagonist

Question 28

Are SSRIs antagonists or agonists?

Answer 28

they are antagonists that bind to SERT which usually reuptakes excess serotonin leaving more freely available in the synapse

Question 29

If EC50 of Drug A is 0.5 and Drug B is 1.4, which has the higher potency?

Answer 29

Drug A

Question 30

ionised molecules readily diffuse over membranes, true or false

Answer 30

false, unionised diffuse more readily because they are non-polar

Question 31

What is Pka?

Answer 31

the pH at which 50% of the drug is ionised and 50% is unionised

Question 32

Which two types of transport can be involved in saturation kinetics

Answer 32

facilitated diffusion and active transport

Question 33

active transport requires ATP and occurs along the concentration gradient, true or false?

Answer 33

false, it does require ATP but occurs against the concentration gradient

Question 34

What does the Henderson hasslebach equation tell us?

Answer 34

how drugs ionise each other at different pH levels

Question 35

Why will a weak base be absorbed in the gut more readily?

Answer 35

because it has a higher pH - more basic conditions which is favourable to a weak base

Question 36

weak acids are ore readily absorbed by the stomach, true or false?

Answer 36

true because it has a lower pH

Question 37

how much body water does the intracellular fluid/water comprise?

Answer 37

2/3

Question 38

what is the equation for the apparent volume of distribution (Vd)?

Answer 38

dose/drug plasma concentration

Question 39

what does a low Vd suggest about the drug distribution in the body?

Answer 39

it is retained in the vascular compartment

Question 40

what does a high Vd suggest about the drug distribution in the body?

Answer 40

the drug can be found in non-vascular compartments such as the muscle and adipose tissue can also find plasma protein binding

Question 41

What is the most abundant plasma-binding protein

Answer 41

albumin

Question 42

What is the bioavailability?

Answer 42

The amount of drug that reaches circulation

Question 43

lipophilic drugs tend to have a high Vd, true or false

Answer 43

true, as they are uptaken by fatty tissue

Question 44

What is the equation for bioavailability (f)?

Answer 44

F = quantity of drug that reached circulation/dose

Question 45

What is the responsibility of cytochrome P450 (CYP450)

Answer 45

It is an enzyme family that can modify the drug making it more excretable and activating drugs in some cases influencing drug interactions

Question 46

What happens during phase II reactions

Answer 46

the drugs are modified to become more polar (different molecular groups added on) and more readily excreted from the kidneys

Question 47

CYP450 is used in which phase reaction?

Answer 47

Phase 1

Question 48

What is clearance

Answer 48

the volume of blood that is completely cleared of drug per unit of time (usually L/hr)

Question 49

What does clearance aid in?

Answer 49

helps determine dosage rate needed to maintain a desired plasma concentration

Question 50

What is the equation for clearance?

Answer 50

CL = rate of drug elimination/drug plasma concentration

Question 51

What is first-order kinetics?

Answer 51

where the rate of elimination increases and the plasma concentration of the drug increases also

Question 52

What is zero-order kinetics?

Answer 52

where elimination reaches a maximum as the elimination mechanisms have become saturated

Question 53

What is the elimination half-life

Answer 53

determines how much time is required for the drug to be eliminated from the body

Question 54

What is the equation for the elimination half-life

Answer 54

0.693 x Vd/CL

Question 55

What do Cox 1 and Cox 2 enzymes produce?

Answer 55

prostaglandins

Question 56

Name a few factors that affect the Vd?

Answer 56

ageing and obesity

Question 57

How do ageing and obesity influence the elimination half-life?

Answer 57

ageing causes a decrease in muscle mass thereby recreated the half-life and obesity causes an increase in adipose disse thereby increasing the half-life