Developing Drugs

• New drugs are constantly being developed. But before they can be given to the general public, they have to go through a thorough testing procedure
• There are 3 main stages in drug testing
• Stage 1

  • In preclinical testing, drugs are tested on human cells and tissues in the lab
  • However, you can't use human cells and tissues to test drugs that affect whole or multiple body systems, e.g. testing a drug for blood pressure must be done on a whole animal because it has an intact circulatory system
• Stage 2

  • The next step in preclinical testing is to test the drug on live animals. This is to test efficacy (whether the drug works and produces the effect they're looking for), to find out about its toxicity and to find the best dosage
  • The law in Britain states that any new drug must be tested on 2 different live mammals. Some people think it's cruel to test on animals, but others believe this is the safest way to make sure a drug isn't dangerous before it's given to humans
• Some people believe think that animals are so different from humans that testing in animals is pointless
• Stage 3

  • If the drug passes the tests on animals then it's tested on human volunteers in a clinical trial
  • First, the drug is tested on healthy volunteers. This is to make sure that it doens't have any harmful side effects when the body is working normally. At the start of the trial, a very low dose of the drug is given and this is gradually increased
  • If the results of the tests on healthy volunteers are good, the drugs can be tested on people suffering from the illness. The optimum dose is found - this is the dose of drug that is the most effective and has few side effects
• Stage 3 - pt.2

  • To test how well the drug works, patients are randomly put into 2 groups. One is given the new drug, and the other is given a placebo (a substance that's like the drug being tested but doesn't do anything). This is so the doctor can see the actual difference the drug makes - it allows for the placebo effect
• Stage 3 - pt.3

  • Clinical trials are blind - the patient in the study doesn't know whether they're getting the drug or the placebo. In fact, they're often double-blind - neither the patient nor the doctor knows until all the results have been gathered. This is so the doctors monitoring the patients and analysing the results aren't subconsciouly influenced by their knowledge
  • The results of drug testing and drug trials aren't published until they've been through peer review. This helps to prevent false claims
• The placebo in drug testing is when the patient expects the treatment to work and so feels better, even though the treatment isn't doing anything
• Peer review is when other scientists check that the work is valid and has been carried out rigorously