Zusammenfassung der Ressource
B1.3 The Use And Abuse Of Drugs
- B1.3.1 Drugs
- Drugs affect our body chemistry. Medical drugs are developed and tested
before being used to relieve illness or disease. Drugs may also be used
recreationally as people like the effect on the body. Some drugs are
addictive. Some athletes take drugs to improve performance. People cannot
make sensible decisions about drugs unless they know their full effects.
- Scientists are continually developing new drugs.
- When new medical drugs are devised, they have to be
extensively tested and trialled before being used. Drugs are tested
in a series of stages to find out if they are safe and effective.
- New drugs are extensively tested for toxicity, efficacy and dose: in the laboratory, using cells, tissues and live
animals and in clinical trials involving healthy volunteers and patients. Very low doses of the drug are given at
the start of the clinical trial. If the drug is found to be safe, further clinical trials are carried out to find the
optimum dose for the drug. In some double blind trials, some patients are given a placebo. Neither the doctors
nor the patients know who has received a placebo and who has received the drug until the trial is complete.
- Statins are a group of medicines that lower the level of
low-density lipoprotein (LDL) cholesterol in the blood.
- Thalidomide is a drug that was developed as a
sleeping pill. It was also found to be effective in
relieving morning sickness in pregnant women.
- Thalidomide had not been tested for use in
pregnant women. Unfortunately, many babies
born to mothers who took the drug were born
with severe limb abnormalities. The drug was
then banned. As a result, drug testing has
become much more rigorous. More recently,
thalidomide has been used successfully in
the treatment of leprosy and other diseases.
- Drugs change chemical processes in the body.
People may become dependent on the drug or
addicted to it, and may suffer withdrawal symptoms
if they stop taking the drug.
- Alcohol and nicotine are legal
recreational drugs. However, misuse
of them can cause health problems.
- Alcohol contains ethanol, a depressant which slows down signals in the nerves
and brain. Alcohol is addictive. Long-term effects include damage to the liver
and brain. Nicotine is the addictive substance in tobacco smoke. It reaches the
brain within 20 seconds and creates a dependency so that smokers become
addicted. Smoking increases the risks of: heart disease and strokes;
miscarriage, premature birth and low birth weight; lung, mouth and throat cancer.
- Illegal drugs include prescription drugs that have been dangerously modified and substances that are banned by law.
Ecstasy, cannabis and heroin are illegal recreational drugs. Using them can cause health problems.
- Heroin and cocaine are very addictive.
Like ecstasy, they can damage the
heart and circulatory system. Cannabis
smoke contains chemicals that cause
mental illness in some people.
- The overall impact of legal drugs
(prescribed and non-prescribed) on
health is much greater than the impact of
illegal drugs because far more people
use them.
- There are several types of drug that an athlete can use to enhance performance. Some of these drugs are banned
by law and some are legally available on prescription, but all are prohibited by sporting regulations. Examples include
stimulants that boost bodily functions such as heart rate; and anabolic steroids which stimulate muscle growth.