Testing medicines

• Where were medicines extracted from in the past?

  Plants, such as foxglove, which was used to extract the heart drug digitalis.
• Where was the painkiller aspirin extracted from?

  Willow trees
• Where were drugs also extracted from?

  Microorganisms, the scientist Alexander Fleming discovered penicillin in the mould penicillium.
• Where are most drugs made by now?

  Made my chemists working for pharmaceutical companies, but the starting point is still often a chemical extracted from a plant.
• What do we test first with a new drug?

  Check the toxicity of the drug to make sure its safe for humans. We then need to check that the drug is effective. Finally we need to work out the best dose of the drug.
• What is the first stage of drug testing?

  Preclinical testing, which is not tested out on humans because the drug may be toxic. Preclinical testing is carried out on cells, tissues and on live animals.
• What is the second stage of drug testing?

  Clinical testing, which is carried out on humans. In the first stages of clinical testing, very low doses of the drug are given to healthy volunteers. This is to check the drug is safe in humans. If the drug is safe, clinical testing continues to find the optimal dose.
• What is a placebo?

  A tablet or injection with no active drug in it. Some patients will get better if given a placebo because they think they're being treated so they believe they are going to get better (psychological effect).
• What is a double-blind trial?

  The test group receive the active drug. The placebo (control) group receive a dummy drug which looks the same as the test drug but has no active ingredient.

  In a double-blind trial, neither the patients nor the doctors know which people are receiving the active drug or which people are receiving the placebo. This is done to stop bias incase the doctors pay closer attention to the people receiving the active drug.