1. © Oxford University Press 2011 IB1.12.4 Testing new drugs Testing new drugs

2. © Oxford University Press 2011 IB1.12.4 Testing new drugs New drugs are tested in laboratories on human tissue andanimals to predict how the drugs will behave in when administered to humans.

3. © Oxford University Press 2011 IB1.12.4 Testing new drugs If they pass the laboratory tests, the drugs are tested on human volunteers in clinical trials. The volunteers are divided into control group – given a placebo (dummy pill) andexperimental group – given the real drug At first, very low doses of the drug are given to volunteers. Then, doses are increased to find the dose that works best.

4. © Oxford University Press 2011 IB1.12.4 Testing new drugs The placebo  Neither the doctors nor the patients know who is getting the placebo and who gets the real drug, until the end of the trial. This is called a double blind trial. It makes the trial fair.  Sometimes, clinical trials do not have a placebo. If the patients are very ill, it would not be ethical to give them a placebo because they need treatment. In this case, the new drug is tested against the best current treatment. Once again, the trial is double-blinded.

5. © Oxford University Press 2011 IB1.12.4 Testing new drugs At the end of the clinical trial, the control groupandexperimental group If the drug makes a real difference and causes no harm, it is licensed for use. However, some drugs are recalled when they are used on many more people and new side-effects occur. are compared to see if there is any real difference between them.  