discovery and development of drugs

what are examples of drugs that are developed from plants?

• aspirin (lowers fever) = willow

• digitalis (treats heart problems) = foxglove

what is an example of a drug that was developed from microorganisms?

• penicillin:
  Alexander Fleming found that the mould was producing a substance (penicillin) that was killing the bacteria on his agar plate

order of drug testing:

1. human cells/tissues

2. live animal

3. two different live mammals

4. healthy human volunteers

5. people suffering from the illness

6. two groups of patients (placebo)

7. peer review before publication (prevent false claims)

why are drugs tested on live animals?

• can’t use human cells/tissues to test drugs that affect the entire body/multiple body systems (e.g. testing for blood pressure)

what is tested for on the test for live animals?

• efficacy (whether the drug works)

• best dosage (concentration and how often it should be taken)

• toxicity (how harmful it is)

why is the drug tested on healthy volunteers?

• looking for harmful side effects when the body is working normally

why is the drug tested patients?

• find the optimum dose (most effective with the least side effects)

how does the placebo work? why is it used?

1. patients are randomly placed in two groups

2. one group = new drug; other group = placebo (placebo effect because clinical trials are blind)

the doctor can see the difference the drug makes

why are clinical trials often double-blind?

• doctor and patient both don’t know whether they are getting the drug or placebo

• doctors are not subconsciously influenced

what is preclinical testing?

using cells, tissues and live animals

what is clinical testing?

using volunteers and patients