Sant Joan de Déu Barcelona - Hospital

4. Methodology of clinical trials

clinical trial
secondary effect
  • Get to know the methodology used in clinical trials and its experimental sequence.

The sequence of the clinical trial research methodology always begins with the investigation of the disease, development of the drug and animal testing, in order to make tests on humans at a later stage.

These human trials must pass through various phases before the drug is launched in the market:

  • PHASE 1: In case we work with paediatric medicines we give the drug to a small group of children (healthy or sick), to see what happens when we handle a small dose. If the tolerance level of the drug is correct, we can move on to the next phase.
  • PHASE 2: Now, with a larger group (100-300 patients), we want to see the effect of the drug on the disease and possible side effects, in order to know the optimal dose: more effective and safer, with very little amount of medicine.
  • PHASE 3: Now, with hundreds or thousands of patients (depending on the disease), as we already know what works and what the dose is, we can compare the treatment with an existing one, if possible, and if not, we compare it with the placebo.

Comments and suggestions

We would be love to hear your opinion about our resources.

We all learn form your experience

If you want to send us examples of the activities you have done in class, we can publish them on the web.

This section will grow with everybody's effort.

Send your resources to

Helps us improve

Please, fill in our quality questionnaire and we will take into account your experience to elaborate the next materials.