| Morphine & heroin
Morphine is a powerful painkilling drug that acts directly on
the central nervous system. It is called an opiate because it comes from
the opium poppy. It is prescribed to relieve severe chronic pain, such
as cancer pain, and after severe injury or surgery. Morphine has side
effects such as drowsiness and blurred vision, and it is very addictive.
Heroin is manufactured from morphine and is
even more dangerously addictive. But it is useful to treat severe pain
in terminally ill patients, and it causes fewer unpleasant side effects
than morphine. Both substances are used illegally as recreational drugs,
and this is very dangerous.
Cannabis
Cannabis is an illegal drug that can be smoked, producing feelings of
well-being. But like tobacco it can cause lung cancer and bronchitis.
Unlike tobacco, it can cause permanent damage to the mental health of
its users. Research has shown that cannabis has some useful painkilling
properties, but it is illegal to prescribe it for this use.
The impact on health
All drugs have the potential to damage our health, because they change
chemical processes in the body. Addictive recreational drugs may damage
our health indirectly by reducing the amount of money available to buy
food, and by placing users in dangerous situations. Injecting any drug
with a needle and syringe that someone else has used may lead to a number
of diseases from infected blood, including HIV and hepatitis. Users of
illegal drugs may turn to crime to pay for their habit, and this affects
the lives of other people.
A research report in 2006 classified various drugs according
to their health and social risks, without reference to whether they are
legal or not. In the report, heroin and cocaine are the most dangerous
two drugs, alcohol is the fifth most dangerous and tobacco is ninth.
[ This page has been adapted from www.bbc.co.uk/schools/gcsebitesize/science
] |