Developing new medicinesSpec 5.20
Developing a new medicine, including a new antibiotic, takes many stages. Each stage checks that the medicine is safe and that it works.
- Discovery: finding a chemical that might treat the disease. These may come from natural sources, such as plants or microorganisms, or be designed in a laboratory.
- Development: the chemical is studied and improved, and a way to make it as a medicine is worked out.
- Preclinical testing: the medicine is tested in the laboratory on cells and tissues, and then on live animals, to find out if it is toxic and whether it works.
- Clinical testing: the medicine is tested on people. It is first given to a small number of healthy volunteers to check it is safe, then to patients to check that it works and to find the right dose.
Only a medicine that passes all the stages can be used to treat patients. The testing protects people from harmful or ineffective medicines.
Quick check
Why can antibiotics not be used to treat viral infections?
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Antibiotics inhibit cell processes in bacteria; viruses are not cells and reproduce inside host cells.
Triple only: why is an inoculating loop heated in a flame before use?
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To sterilise it by killing any microorganisms on it.
Triple only: in the core practical, what does a larger clear zone show?
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The substance is more effective at stopping bacteria growing.
Name the four stages in developing a new medicine in order.
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Discovery, development, preclinical testing, clinical testing.
Triple only, Higher tier: what is a hybridoma cell?
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A cell made by fusing an antibody-producing lymphocyte with a tumour cell; it divides and produces antibodies.