Developing new medicines

-A good medicine is;

• Effective-it must prevent or cure the disease it is aimed at, or at least make you feel better
• Safe- the drug musn't be toxic and there must be no unacceptable side effects
• Stable-you need to be able to use the medicine under normal conditions and store it for sometime 
• Successfully taken in and removed from your body-a medicine is no use unless it can reach its target in your body. Then your body must be able to remove the medicine once it has done its work 

1. Researchers target a disease and develop ideas for treatments

2. The search for possible drugs includes the computer design of molecules and screening hundreds of thousands of chemicals 

3.Possible drugs are made (synthesised) in the lab

4. In vitro screening-the potential medicines are tested on cell cultures,tissue cultures and isolated whole organs in the lab. Many chemicals fail at this stage because they don't work or are toxic

5. Animal testing- the small number of chemicals which make it this far are now tested on animals. This finds out more about how they work in whole living organisms. It tells us what dose is needed and it there is any side effects

6. Animal testing continues, looking at the effect of longer term use of medicine 

                                                                  OR

6. Clinical testing on humans begins with phase I on a small number of healthy volunteers. This looks at the safety of medicine in people 

7. Human phase II trials run with a small number of the patients suffering from the diseasee. This is where the scientists can really begin to see if the drug will be safe and effective

8. Human phase III trial continues with a larger number of patients 

9.When medicine has passed all the tests set down in law, it will be granted a licience. Now your doctor can use the new medicine to treat your illness

10. Once the medicine is used, phase IV trials continue. The medicine will be monitored for as long as patients use it.This makes sure it works and is as safe as possible 

-Thalidomide is a medicine which was developed in the 1950s as a sleeping pill. 

-It was discovered that thalidomide stopped sickness in pregnancy. Because it seemed safe for adults, it was assumed that it was safw for unborn children

-Doctors gave it to pregnant women to stop morning sickness

-It affected many women and they gave birth to babies with severe limb deformities 

-Since the Medicines Act in 1968, new medicines must be tested on animals to see if they have an effect on developing fetuses 

-Thadlidomide can also be used to treat leprosy and automimmune disease (where the body attacks itself)