DRUG DEVELOPMENT AND TESTING

• Microorganisms and plants have been evolving for millions of years and along the way they've evolved to produce a range of substances that are able to do all sorts of things including killing pathogens
• Instead of having to develop all of our drugs from scratch we've been able to take these substances from them and either use them directly as medicines or sometimes modify them in a lab of it first and then use them as medicines
• Substances from nature used as medicines


  • Aspirin (from willow tree bark)
  • Heart drug Digitalis (from foxglove plants)
  • Penicillin (from Penicillium fungus)
• Efficacy


  How well the drug works, how well it produces the desired effect
• Toxicity


  How harmful the drug is, whether it damages cells or has side effects
• Dosage


  How much of the drug or what concentration should be given to treat the disease with the fewest side effects
• Clinical trials should be blind and use a placebo
• Blind trial


  Volunteers don't know if they are taking the real drug or a placebo
• Double-blind trial


  Neither the volunteers nor the doctors know who is taking the real drug or placebo
• The purpose of blind and double-blind trials is to avoid unconscious bias in case doctors pay closer attention to people receiving the active drug
• Peer review is central to science, where studies are analyzed by other scientists to check fairness and prevent false claims
• Sources of new medicines


  • Extracted from plants
  • Extracted from microorganisms
  • Synthesized by chemists
• Drug testing


  1. Preclinical testing on cells, tissues, or live animals in case the drug is extremely toxic

  2. Clinical testing on healthy volunteers to check safety

  3. Clinical testing on patients to find optimal dose
• Placebo


  Tablet or injection with no active drug