Drugs

A drug is a chemical that changes the way your body works.

Types of drugs:

• painkillers
• stimulants 
• halucinogens
• antibiotics

Medical drugs make people feel better when they are ill.
Painkillers block nerve impulses.

What is a difference between medical drugs and recreational drugs?
The difference is that medical drugs are used when a person is ill and needs his/her body to function normally and recreational drugs are drugs that are taken by people when they don't need them.

People can become addicted to a drug, which means that it is hard for them to give it up. It can damage the lungs, brain and a liver.

Sometimes drugs are not effective because the body got used to it when taking regularly.

Antibiotics
Antibiotics can't be used to kill viruses because they live in body's cells, so it would have to damage the cell to kill viral pathogens.

Penicilin
Penicilin is an antibiotic discovered by Sir Alexander Fleming in 1928. He left petri dishes with bacteria on in a sink whilst he went on a holiday. After he returned he found some mould and bacteria developing on the petri dish.

This discovery was so important because it saved many soldiers' lives during WW2. The first people who received penicillin were Ernst Chain and Howard Florey.

Drug trials
Drugs must be tested before they can be sold to see if they are safe and effective. This is checked in a series of stages:

1. in the laboratory using cells and tissues
2. in clinical trials - this involves usually three phases with healthy volunteers and patients.

Double blind trials are when one patient is given a placebo and the other one a drug. Neither the patients nor the doctors know who received placebo and who received a drug.

Problems with drugs
Some people use drugs recreationally and they can become addicted which can cause a big harm to the body. Some drugs are legal (eg. nicotine), others aren't (eg. heroine). Some people don't take drugs sensibly, they overuse them, eg. sleeping tablets.

Thalidomide
It was developed as a sleeping tablet in first place, but women found it to be effective to make them feel better during morning sickness when pregnant. Although, the drug was not tested for this use, more and more women started taking it. Many babies of those women were born with severe limb abnormalities. It was then banned.