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Science

Drugs and health

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Drugs are substances that change chemical reactions in the body. Medical drugs relieve disease and illness, and are extensively tested before being used. Thalidomide is a drug that caused unexpected and damaging side effects to babies in the last century.

Recreational drugs such as alcohol and tobacco are taken by people because they like the effects they have on their bodies, but they are addictive. Heroin and cocaine are illegal recreational drugs that are very addictive.

Drugs and drug testing

Drugs

Drugs are substances that cause changes to the body. Some drugs can help the body, but others can harm it. Some drugs can be extracted from natural sources and their existence has been known about for a long time. For example, willow bark is known to have been used by the ancient Greeks to help cure fevers and pains. It was later discovered that the active ingredient was salicylic acid. This was modified by chemists into the substance we call aspirin, which is less irritating to the stomach than salicylic acid.

salicylic acid and aspirin molecules

Drug testing

New medical drugs have to be tested before they can be prescribed for patients. They are tested in a laboratory to check that they are not toxic, and later they are trialled using human volunteers. At this point, any potential side effects should show themselves. Most substances do not pass all the tests and trials, so drug development is expensive and takes a long time.

Watch

You may wish to view this BBC News item from 2006 about a drugs trial that left six volunteers very ill.

Medical drug trials are not without risk. Sometimes very severe and unexpected side-effects appear.

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