Where do medicines come from?

pills

 

 

 

 

Scientists know a lot about the body and about illnesses, but there’s still a lot they don’t know – about the brain for instance. Scientists have also developed millions of chemicals, plant extracts, genes and antibodies. New ones are being discovered or created with computer programmes every day. Any of them might be the basis of a new medicine.

But how can we tell which things will work on which diseases or conditions? And even if they do work, what side effects might they might have? What is the correct dosage (the amount we need to give to the patient) and how can we get it to the right part of the body?

Computers, cells, and animals

Computers and cell samples give us a lot of answers. On-screen models help scientists to select from the millions of chemicals and other possible treatments to find a few hundred that might work. Highly automated 'in vitro' (which is Latin for 'in glass') experiments in test tubes can then give us an idea of what happens when the treatment is used on real cells or tissue.

But a test tube is not the same as a living body. We are all amazingly complex. We each have about 100 billion brain cells, 100,000 miles of blood vessels and over 60 organs wrapped up inside us and all interconnected. We don’t know enough to program even the most powerful computer to mimic all this.

So it is difficult to predict for certain what will happen when a new gene or chemical is placed in such a complex living body. We have no choice but to try it in a living creature and that is where the animals come in. To use the treatment at this stage on a person would be too big a risk. Would you risk it?

Safety testing

If a treatment works after trying it in animals, it might be time to introduce it to human beings, but first the medicine must be tested for safety. The law is that every new medicine is tested on two species of animals before it is used on people. This is to minimise the risk of dangerous side effects like raised blood pressure or liver failure. Most of these tests involve giving a mouse or rat a dose of the medicine and then taking blood and urine samples.

Caring for animals

It is very important that the animal suffers as little as possible because that can affect the results of the tests. Specially trained technologists watch over the animals and make sure they are well treated and are kept as comfortable as possible.

Clinical trials and beyond

It is only after all these stages that we can begin to test a new medicine on a human being. It is given to a small group at first and then larger groups in three phases of 'clinical trials'. For every animal that is used in creating and testing a successful medicine, about 15 human volunteers will be involved at some stage in testing.

Even now, after all the experiments with computers, cell samples and animals, many medicines fail during the clinical trials. The reason that more do not fail and that volunteers are not usually harmed in trials is because animal research gives us so much valuable information. That is why animal research remains essential for the time being. Without it, we simply cannot have any new medicines. 

Leaflet From test tube to patient

Our leaflet From Test Tube to Patient: The Making of a Medicine provides more information.

 

 

You might also like to test your knowledge by trying our activity called The Shuffle.

 

IMAGE © ISTOCKPHOTO.COM/KUTAYTANIR

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