Stimulant-Increases nerve and
brain activity-Nicotine, caffeine,
Ale medicines are
drugs, but not all drugs
drugs are illegal
Certain drugs can be extracted
from natural sources, and have been
known about for a long time. For
example, willow bark was used by
the ancient Greeks to help cure
fevers and pains. It was later
discovered that the active ingredient
was salicylic acid.
MOst drugs are tested on animals.
In clinical trials, one group of volunteers - called the test
group - receives the new drug. Another group - the
control group - receives the existing drug for that illness.
There are two main types of clinical trial:: Blind trials
– the volunteers do not know which group they are in
but the researchers do and double-blind trials – neither
the volunteers nor the researchers know which group
the volunteers are in until the end of the trial