Childrens Illustrated Encyclopedia

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167

IF YOU ARE SICK, the doctor might give you a

drug. Drugs, or medicines, are substances used

in the treatment of illnesses. They can relieve

the symptoms (effects) of a disease, ease pain, and

prevent or cure illnesses. Drugs are also used to treat a

wide range of emotional disorders, such as depression.

There are thousands of different kinds of drugs in use

today. Each drug has a specific function and often

acts on a single part of the body, such as the

stomach. There are many sources of drugs.

They may be natural or synthetic

(artificial). Medicinal plants and herbs

yield natural drugs that have been in use for

thousands of years. Scientists search constantly

for new drugs and often make them

from chemicals. In many cases, the

discovery of a drug has

eased suffering and saved

many lives. Antibiotics, such

as penicillin, cure infections

that would have been fatal

70 years ago.

Tablets and capsules contain

carefully measured amounts

of drugs. When they are

swallowed, the drugs slowly

filter into the bloodstream via

the digestive system. Some

tablets have a coating that

dissolves slowly, releasing the

drug at a controlled rate.

TYPES OF DRUG

Different drugs have
different uses. They range

from antibiotics (for
treating infections) to

painkillers, such as aspirin.
Anesthetics are used to put

patients to sleep before
surgery. There are different

ways of taking drugs. They
can be swallowed, injected,

put on the skin, used in
a spray, or inhaled.

Some drugs, particularly those for small

children, are dissolved in a sweet-tasting

syrup. Special spoons that hold a fixed

amount of liquid ensure that the patient

receives the correct dose. Medicines

can also be given by oral syringe.

Some drugs, such as

antihistamines for

treating allergies

(sensitivity to certain

substances), work more

quickly if they are

injected directly into the

bloodstream through

a needle and syringe.

Some powdered drugs

dissolve in water,

which helps them

enter the bloodstream

more rapidly than if

they are taken as pills.

SOURCES OF DRUGS

In the past, all drugs used

in treating illnesses came

from natural sources,

particularly herbs and

plants. Today, most drugs

are made from chemicals,

and some are made by

genetic engineering, a

method in which the cells

in bacteria or yeasts are

altered to produce drugs.

The heart drug

digitalis originally

came from a

flower called

the foxglove.

Some drugs, such as

insulin (for treating

diabetes), are made

in human form using

engineered bacteria.

DRUG ADDICTION

Many drugs, including some of

those recommended by doctors, are

addictive. This means that the user

becomes dependent on them. Drug

addiction can lead to illness and

death. The use of many dangerous

drugs such as heroin, crack, and

cocaine is illegal. However, other

addictive drugs, such as alcohol

and nicotine (in cigarettes), are

not controlled by law.

Aspirin is made

from chemicals

like those found

originally in

willow tree bark.

The antibiotic

penicillin first

came from a

mold called

penicillium.

Tablets containing

drugs are made

with a smooth

shape so that

they are easy

to swallow.

Chemistry

Disease

Flowers and herbs

Health and fitness

Medicine

Medicine, history of

The body can

absorb creams and

ointments through

the skin. Medicinal

creams are

often used to treat

skin disorders.

Drugs can be dangerous.

Today, many containers

are made with specially

designed tops that

are difficult for

children to remove.

Drugs

ORAL MEDICINES

Many drugs are taken

orally (by mouth). The

drug passes through

the digestive system and

into the bloodstream,

which carries the drug

to the relevant part

of the body.