Testing Medicines

• Where did new medicines often come from in the past?

  Plants and microorganisms
• What drug was extracted from the foxglove plant?

  Digitalis
• From which tree was aspirin extracted?

  Willow tree
• What is the current method for developing most new drugs?

  Synthesized by chemists in pharmaceutical companies
• What must all new drugs be tested for?

  Toxicity, effectiveness, and optimal dose
• What is the first stage of drug testing called?

  Preclinical testing
• What types of subjects are used in preclinical testing?

  Cells, tissues, or live animals
• Why is preclinical testing not carried out on humans?

  A drug could be extremely toxic
• What happens after preclinical testing?

  The drug undergoes clinical testing in humans
• What is the purpose of the first stage of clinical testing?

  To check that the drug is safe in humans
• What is given to healthy volunteers during the first stage of clinical testing?

  Very low doses of the drug
• What is the goal of continuing clinical testing after initial safety checks?

  To find the optimal dose with fewest side effects
• What is a placebo?

  A tablet or injection with no active drug
• Why do some patients improve when given a placebo?

  They believe they are being treated
• What is a double-blind test?

  Neither patients nor doctors know the treatment
• What is the purpose of a double-blind trial?

  To stop bias in treatment observation
• What are the stages of drug testing?

  1. Preclinical testing

  • Conducted on cells, tissues, or animals

  1. Clinical testing

  • Initial safety checks on healthy volunteers
  • Finding optimal dose for treatment
• What are the key differences between preclinical and clinical testing?

  • Preclinical testing:
  • Not on humans
  • Focus on toxicity and initial safety
  • Clinical testing:
  • Conducted on humans
  • Focus on safety and effectiveness