THERAPEUTICS

Question 1

what is pharmacodynamics?

Answer 1

what the drug does to the body

Question 2

what is pharmacokinetics?

Answer 2

what the body does to the drug

Question 3

what is a medicinal product?

Answer 3

a substance or combination presented as having properties for treating or preventing disease in human beings eg drugs

Question 4

what is a medical device?

Answer 4

anything as simple as a plaster all the way to an MRI machine (any instrument/ machine/ apparatus)

Question 5

what are the 2 methods by which drugs enter the system?

Answer 5

• Active transport

- Passive diffusion

Question 6

what 4 processes does pharmacokinetics involve?

Answer 6

• absorption
• distribution
• metabolism
• excretion

Question 7

where is the main site of metabolism in pharmacokinetics?

Answer 7

liver

Question 8

where is the main site of excretion in pharmacokinetics?

Answer 8

kidneys

Question 9

what is a formulation?

Answer 9

the pharmaceutical form of a drug eg tablet or capsule

Question 10

what does liberation mean?

Answer 10

the release of a drug from its pharmaceutical form

Question 11

what is drug absorption?

Answer 11

drug being moved into systemic circulation after being administered

Question 12

what is distribution?

Answer 12

movement of drug into tissue from systemic circulation

Question 13

what is drug metabolism?

Answer 13

conversion of drug into other chemicals in the body

Question 14

what is drug excretion?

Answer 14

elimination of medicine from the body

Question 15

what is the formula for calculating the volume of distribution?

Answer 15

vol of distribution = dose/ plasma conc

Question 16

what does lower vol of dist (Vd) mean?

Answer 16

drug stays in blood stream

eg warfarin

Question 17

what does higher vol of distribution mean?

Answer 17

drug moves into tissues

eg propranolol

Question 18

what is therapeutic index?

Answer 18

the ratio of the dose that results in an undesired effect to that which results in a desired effect

Question 19

what does therapeutic drug monitoring involve?

Answer 19

clinical practice of measuring specific drugs at designated intervals to maintain a constant concentration in a patients bloodstream, thereby optimising individual dose regimens

Question 20

name some drugs with a narrow therapeutic index

Answer 20

• aminoglycosides
• ciclosporin
• carbamazepine
• digoxin
• flecainide
• lithium
• pheytoin
• rifampicin
• theophylline
• warfarin

Question 21

what are some factors affecting drug absorption (5)?

Answer 21

• formulation
• motility of the gut
• food in stomach
• degree of 1st pass metabolism
• lipid solubility

Question 22

what are some factors affecting drug distribution (4)?

Answer 22

• lipid solubility
• degree of ionisation
• drugs which are highly protein bound
• pharmacogenetics

Question 23

what is the only type of drug that can exert an effect?

Answer 23

unbound drugs

Question 24

what is a ‘free drug’?

Answer 24

active drug

Question 25

which fruit acts as an enzyme inhibitor?

Answer 25

grapefruit

Question 26

what is meant by affinity?

Answer 26

how actively the drug binds to the receptor

Question 27

what is meant by efficacy?

Answer 27

ability of drug to elicit a response when it binds to the receptor

Question 28

what is meant by potency?

Answer 28

a measure of the amount of drug required to produce an effect

Question 29

what is an agonist?

Answer 29

drug that activates a receptor

Question 30

what is an antagonist?

Answer 30

a drug which blocks a receptor

Question 31

what is a partial agonist?

Answer 31

drug that binds to and activates a given receptor, but only has partial efficacy at the receptor (relative to full agonist)

Question 32

describe competitive inhibition

Answer 32

- this blocks an enzyme at its active site | - it is temporary

Question 33

describe non-competitive inhibition

Answer 33

this stops an enzyme from working by changing the shape of the active site by combining to the allosteric site (not active site)

Question 34

what is bioavailability?

Answer 34

the proportion of the administered drug that reaches the systemic circulation, must first pass the intestinal wall and the portal circulation to the liver

Question 35

what does the area under the bioavailability curve indicate?

Answer 35

the extent of the absorption

Question 36

what is the peak concentration of the bioavailability curve?

Answer 36

the highest conc of a drug in the plasma after a dose is given

Question 37

what is the median toxic dose?

Answer 37

the dose at which toxicity occurs in 50% cases in the population

Question 38

what does a phase 1 metabolic reaction primarily involve?

Answer 38

oxidation

Question 39

what does a phase 2 metabolic reaction primarily involve?

Answer 39

conjugation

Question 40

describe characteristics of phase 1 metabolic reactions

Answer 40

- involves a biotransformation of a drug to a more polar metabolite - involve CYP enzymes - these reactions mostly oxidation but can be reduction or hydrolysis

Question 41

what happens to phase 1 product in phase 2 metabolic reaction?

Answer 41

phase 1 product is bound to conjugate | -drug is now more hydrophilic

Question 42

what is drug clearance?

Answer 42

the volume of fluid cleared of a drug per unit time

Question 43

what is half-life?

Answer 43

the time for the plasma concentration to fall by 50% of what it was at equilibrium

Question 44

what is distribution half-life?

Answer 44

when plasma levels fall to half what they were due to distribution of the drug to body tissue

Question 45

what is elimination half-life?

Answer 45

when plasma levels fall to half of what they were due to the drug being metabolised and eliminated

Question 46

what is 1st order elimination?

Answer 46

rate of drug elimination is dependent on plasma conc

Question 47

what is zero order elimination?

Answer 47

rate of elimination is constant and independent of plasma conc

Question 48

how does the elimination half-life relate to the time taken for drug to be eliminated from the body ?

Answer 48

x5 elimination = time at which the drug is eliminated

Question 49

what are the 5 classes of drugs?

Answer 49

- beta-blockers - ACE inhibitors - ARBs (angioptensin 2 receptor blockers) - cholesterol-lowering drugs - calcium channel blockers

Question 50

what do beta-clockers generally end in?

Answer 50

-alol or -lol

Question 51

what do beta-blockers do?

Answer 51

block the beta-adrenergic receptors---->blocks the sympathetic nervous system to heart and lungs, primarily slows heart rate, reduces BP

Question 52

what are some common side effects of beta-blockers (4)?

Answer 52

- bradycardia - hypotension - congestive heart failure (if HR too low) - bronchospasm

Question 53

what do ACE inhibitors typically end in?

Answer 53

-pril

Question 54

what do ACE inhibitors do?

Answer 54

inhibit angiotensin converting enzymes in the lungs (ACE) ---->lower BP

Question 55

what are some common side effects of ACE inhibitors (3)?

Answer 55

- chronic cough - angioedema - hypotension

Question 56

what do ARB's (angiotensin II receptor blockers) typically end in?

Answer 56

-sartan

Question 57

what do ARBs do?

Answer 57

block angiotensin II-which is vasoconstrictor-->lower BP

Question 58

what do cholesterol-lowering drugs generally end in?

Answer 58

-statin

Question 59

what do cholesterol-lowering drugs do?

Answer 59

inhibit fat adsorption and inhibit cholesterol production

Question 60

what are some common side effects of cholesterol-lowering drugs (4)?

Answer 60

- steatorrhoea - muscle weakness - diarrhoea - abdominal discomfort

Question 61

what do calcium channel blockers generally end in?

Answer 61

-pine

Question 62

what do calcium channel blockers do?

Answer 62

block calcium channels

Question 63

what are some common side effects of calcium channel blockers (3)?

Answer 63

- bradycardia - hypotension - heart failure

Question 64

what is meant by ED50?

Answer 64

-dose of medicine that produces desired pharmacological effect in 50% of the studied patient population that takes the medication

Question 65

what is meant by TD50?

Answer 65

-median toxic dose of drug/toxin-toxicity occurs in 50% cases

Question 66

What is better a small or large therapeutic index?

Answer 66

Large

Question 67

What is an example of a drug with a large therapeutic index?

Answer 67

Paracetamol