3.1.9 Discovery & Development of Drugs

• What do plants produce to defend themselves against pests and pathogens?

  Chemicals.
• Where does aspirin come from?

  Willow bark.
• What does aspirin treat?

  Pain, fever, and inflammation.
• Where does digitalis come from?

  Foxgloves.
• What does digitalis treat?

  Heart conditions.
• How was penicillin discovered?

  Accidentally - Fleming realised the mould killed bacteria.
• Who discovered penicillin?

  Alexander Fleming.
• Most new drugs are synthesised by who?

  Chemists in the pharmaceutical industry.
• What three things are new drugs commonly tested for?

  Toxicity, efficacy and dosage.
• Where does preclinical testing take place?

  A laboratory.
• What does preclinical testing use?

  Cells, tissues and live animals.
• Clinical trials use who?

  Healthy volunteers and patients.
• What amount of dosage is given at the start of a clinical trial?

  Very low.
• If the drug is found to be safe, why are further clinical trials then carried out?


  To find the optimum dose.
• What is efficacy?

  The effectiveness or ability to produce a desired result.
• What are some patients given in a double blind trial?

  A placebo.
• What is toxicity?

  The degree to which a substance can cause harm or damage to living organisms.
• What is dosage?

  The amount of a medication or substance given to an individual.
• Stages of drug development:

  • Stage 1 - Test the drug on human cells and tissues.
  • Stage 2 - Test the drug on live animals.
  • Stage 3a - Test the drug on healthy volunteers to find the maximum dosage before side effects occur.
  • Stage 3b - Test the drug on patients that suffer from the relevant disease, to find the optimum dosage.
• Why is it important that new medicinal drugs undergo testing before they are used?

  Safety, to determine the optimum dosage and to make sure they are effective.
• What is a placebo?

  A substance or treatment that contains no active drug.
• Why is it important for medical trials to be double-blind?

  • To avoid any bias by the patients and/or researchers.
  • If patients know they received the drug, they may be more likely to report side effects.
  • If researchers know who has been given the real drug, then they may pay closer attention to those patients.
• What is peer review?

  When another scientist checks that the work is valid and has been carried out rigorously.
• What does the law in Britain state about drug testing?

  Any new drug must be tested on two different live mammals.