1. Drugs

2. Drugs
What is a drug?
…A drug is a chemical that changes chemical processes in people’s bodies.
Many drugs derived from natural substances have been known to indigenous peoples for many years eg:
Aspirin from the Willow tree
Nicotine from the Tobacco plant
Old wives tales about herbs etc grown in their garden

3. Drugs can be beneficial but may harm the body:
Medicines are beneficial…
…but an overdose can kill
For most illegal drugs there are negative effects
Other drugs are simply toxic (poisonous)
The overall impact of legal drugs on health is much greater than the impact of illegal drugs, because far more people use them.

4. Drug Trials

5. Drug Trials
Scientists are developing new drugs. These need to be thoroughly tested.
When new medical drugs are devised, they have to be extensively tested and trialled before being used.
They don’t always go well…

6. From: BBC News - 15 March 2006

7. Pre-Clinical Testing
New drugs are tested in the laboratory to find out if they are toxic and to find out whether they work.
These tests often involve the use of animals.
If a drug passes these tests, it is then tested on humans in clinical trials.

8. Clinical Testing – Phase 1
Very low doses of the drug are given to healthy people
This is used to see if there are side effects

9. Clinical Testing – Phase 2
If the drug is found to be safe, further clinical trials are carried out
Check safety on a larger scale
Find the optimum dose and delivery for the drug

10. Clinical Testing – Phase 3
Clinical trials on Patients to test effectiveness
Much larger study
Some patients are given a placebo which does not contain the drug.

11. It is usually a ‘Double Blind’ trial in which:
Technicians prepared the jabs. Some contained the drug and some do not.
The nurses know which volunteer to give each jab to, but not what is in them.
Neither the doctors nor the patients know:
who has received a placebo and
who has received the drug
…until the trial is complete.

12. The volunteers that are given the placebo are the control group
Medicines must work better than a placebo to be worth using.
Blind trials are essential because:
Even fake medicine makes you feel better.
Doctors can be biased too. If they think something will work, they spot more improvements in their patients.