Development of Drugs & Drug Testing
- Whenever new drugs are developed, they first need to be tested for effectiveness and side-effects, before they can be sold to the general public
- These are known as clinical trials and are crucial to avoid exposing the public to drugs that may pose a risk to their health
- Drug testing has not always been this scientific or regulated in the past
Digitalis soup
- William Withering was an English scientist from the 1700s
- He is best known for his work on using digitalis as a treatment for swelling caused by heart failure (known as dropsy)
- Withering treated his patients with an extract made from foxgloves, which contains the drug digitalis
- Foxglove is poisonous to humans, so he made different versions of his remedy containing different concentrations of digitalis
- These versions were called his digitalis soup
- He experimented on his patients to find the most effective concentration of digitalis that would treat dropsy without poisoning the patient
Modern methods of drug testing
- Modern drug testing protocols are much more rigorous than those of the past
- The first step is modelling the potential effects of the drug, using computers
- Next, the drug will be tested on human tissues in a laboratory, before being tested on animals
- Should the drug pass these steps without causing any major problems, then it will continue to the clinical trial stage where human test subjects will take it
- There are three phases of testing during clinical trials:
- Phase 1 involves a small group of healthy individuals to determine how the body will react to the drug, the side effects of the drug and the correct dosage that should be taken
- Phase 2 will be done on a larger group of patients (non-healthy individuals who require the drug) to determine the effectiveness of the drug
- Phase 3 involves comparing the drug to existing drugs to see if it works any better. A large number of patients are split into two groups, each of which receives either the new drug or the existing one
Placebos
- Placebos are typically done during phase 2 of a clinical trial
- Patients are split into two groups - one will receive the drug and the other group will be given a placebo, which looks exactly like the drug but contains no active ingredients
- The patients are not told which group they are in
- This provides a way for scientists to determine whether the drug actually works
- Certain patients display what is known as the placebo effect
- This is where a patient will show improvements in their health due to the belief that they are receiving the drug
Double blind studies
- These happen during phase 2 and 3 of clinical trials
- Double blind means that neither the patient nor the doctor knows which patient is receiving the drug or the placebo
- This reduces the effect that the attitude of either doctor or patient may have on the results
- For example, in some cases, a doctor may believe a patient is improving more if they know the patient is receiving the drug
