L2 - sources of drugs and their nature

Question 1

briefly describe the drug discovery process (3 steps)

Answer 1

1. basic research in labs and universities - better understanding of physiology and diseases
2. identification of possible drug targets
3. hypothesis generated

Question 2

what things need to be considered at the start of the drug discovery process?

Answer 2

1. safety
2. ethics
3. does the drug already have patent
4. cost effectiveness

Question 3

why are animal models used in drug development?

Answer 3

to test safety of drugs on body systems similar to humans

Question 4

what are the sources of drugs

Answer 4

natural - plants
compound libraries
combinational chemistry

Question 5

give an example of a naturally sourced drug and its use

Answer 5

morphine - opium poppy - analgesia

Question 6

what is combinatorial chemistry

Answer 6

a way of creating new compounds quickly

reacting molecules with a certain number of attachment points with as many substituents as desired to produce new compounds

Question 7

how can you work out the number of combinations of molecules from combinational chemistry?

Answer 7

attachment points
substituents ^

eg a molecule with 3 attachment points reacted with 9 substituents would give 9^3 combinations (729)

Question 8

what is high throughput screening

Answer 8

screens many compounds very quickly to identify potential biological activity

eg if it binds to a certain enzyme

Question 9

how are structure activity relationships useful in drug development

Answer 9

a drugs structure has profound effects on its activity

a drugs structure can be manipulated (eg groups added) to improve drugs effectiveness

Question 10

how long is pre clinical stage and what occurs in preclinical stage

Answer 10

5-10 years

everything up to human testing

Question 11

what is the purpose of phase 1 clinical trials

Answer 11

1. check drug safety (dangerous side effects)

2. check drug tolerability (unpleasant side effects)

Question 12

what has to happen before phase 1 clinical trials

Answer 12

drug toxicity tested in at least 2 mammals

Question 13

describe process of phase 1 clinical trials

Answer 13

involves a small no. of healthy volunteers exposed to increasing doses of drug

Question 14

purpose of phase 2 clinical trials

Answer 14

to determine drug effectiveness in patients with illness

Question 15

what happens in phase 2a

Answer 15

exploratory phase to determine most effective dose

Question 16

what happens in phase 2b clinical trials

Answer 16

confirmatory phase
more patients
safety and efficacy compared to placebo & current treatments

Question 17

what happens during phase 3 trials

Answer 17

much larger sample (2000 - 10000)
many different groups
several years long

Question 18

when does patent start and how long does it last?

Answer 18

early in pre-clinical development when you have drug of interest
20 years

Question 19

how many people usually in phase 1 trials

Answer 19

40 - 60

Question 20

how many people in phase 2

Answer 20

a - 50 - 200

b - 200- 500

Question 21

what is phase 5 trials

Answer 21

ongoing whilst drug is on market
monitors :
-drug - drug interactions
-rare / long term adverse effects (pharmacovigilance)
efficiency in sub groups (eg elderly and children)