New drugs are being developed all the time. Historically drugs 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.
Certain drugs 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 drug, digitalis which is extracted from the foxglove plant.
Plants are still important in providing new drugs today, but most plant drugs are now created in a laboratory by scientists at pharmaceutical companies. Many of these companies now produce synthetic versions of the plant extracts, and also use these as the starting point to develop new drugs.
New medical drugs have to be tested to ensure that they work, and are safe, before they can be prescribed.
New drugs need to be tested and trialled before doctors prescribe them and patients take them. This allows drugs to be checked for:
There are three main stages of testing:
Preclinical drug trials
Human clinical trials
The placebo effect occurs when someone feels they are better when they have been given a dummy form of the drug, not the drug itself.
To reduce the placebo effect in drug testing:
There is a small amount of risk involved in many choices we take in our lives. There is some risk involved in volunteering to be in a drug trial. Some people choose to do this though. Sometimes sick people volunteer to try a newly developed type of treatment. Other volunteers are healthy. They are paid a small sum of money to participate. Drug testing on humans is an important part of the process described above.