The discovery of new medicines
New medicines are being developed all the time. Historically medicines have come from nature, as parts of plants and microorganisms have been extracted. One of the most famous discoveries was made by Sir Alexander Fleming, who discovered penicillin from the Penicillium mould.
This antibiotic is still very important in the fight against disease.
Plant extracts
Certain medicines can be extracted from natural sources, and have been known about for a long time. For example, willow bark was 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. Another example is the heart medicine, digoxin which is extracted from foxgloves.
Plants are still important today, but most plant medicines are now created in a laboratory by scientists at Relating to medicines and drugs, and their production, sale and use. companies. These companies now have A material made by a chemical process, not naturally occurring. versions of the plant extracts, and use these as the starting point developing new medicines.
Targeted medicine discovery
Gene technology is changing the face of medicine. Studying the genome and proteins of a pathogen can suggest a An antigen or receptor molecule on a pathogen or host cell that could be affected by a medicine. for a new medicine. The target could be an antigen or receptor molecule on the cell's surface. Having found a target, Testing large libraries of subsances to discover which could be developed into new medicines. Usually done by a machine. takes place to try to find a pre-existing substance which will react with the target.
Clinical testing
New medicines need to be tested and trialed before doctors prescribe them and patients take them. This allows them to be checked for:
- safety
- effectiveness
- The most effective amount of drug needed to cure the disease.
Safety
This is important as some drugs are Poisonous., and have other side effects that might be harmful to people.
Effectiveness
Also known as The ability of a drug to cure a condition or relieve symptoms., this checks how well the medicine cures the disease, or improves symptoms.
Dosage
This varies, and has to be closely controlled, as too high a concentration might be toxic. Too low a concentration might not be effective.