New drugs are constantly being researched into and developed. However, before they can be prescribed by a doctor it’s very important that they’re thoroughly tested and trialled. There are a number of stages used by scientists to test the safety and effectiveness of a drug before it’s released:
- First of all, the drug is tested on human cells that have been grown specifically in the laboratory. If the drug damages the cell in anyway or shows no positive reactions then it has failed the test and doesn’t go onto the next stage
- If the results are positive, then the drug is used on live animals to get a better idea of how it will affect humans. In the UK this stage must be carried out. Usually, a specific amount is given to an animal and then any effects are recorded.
- The final stage involves clinical trials on healthy volunteers and patients. To begin with, only a small amount is used. If there are no negative side effects then the drug is given in higher doses until the best, or optimum, amount is found.
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Double Blind Trials
In double blind trials, some patients are given a placebo. A placebo doesn’t contain the drug being tested and only the scientists know who has received it. This is a good way to test whether it is in fact the drug that is causing a particular effect or some other factor, for example a patient just believing that they feel better because they’ve taken a drug. It is only after the trial that the patients and doctors are made aware of who took the real drug and who the placebo.
Statins
Statins are prescribed by doctors for people who are at risk of heart or circulatory diseases. They work by decreasing the amount of cholesterol being produced by the liver and thereby being released into the blood. They do this by inhibiting the enzyme in the liver that produces cholesterol.
Thalidomide
Thalidomide, however, has not had such good outcomes. It was originally developed in the 1950s as a sleeping pill. Then it was discovered that it could be used by women to help alleviate morning sickness. The problem was that no tests had been carried out on how it could affect pregnant women or their unborn child.
It was during the 1960s that it became apparent that thalidomide negatively affected the development of the unborn child. Consequently, many babies were born with severe limb deformities, including short or incomplete arms and legs. In total, over 10,000 babies were found to be affected worldwide. The drug was then banned and stricter guidelines were put in place for more rigorous testing of all drugs. Today thalidomide has been found to assist in the treatment of other diseases including leprosy.