Discovery and Development of Drugs

• Traditionally drugs were extracted from plants and microorganisms:

  • The heart drug digitalis originates from foxgloves.
  • The painkiller aspirin originates from willow.
  • Penicillin was discovered by Alexander Fleming from the Penicillium mould.
• Most new drugs are synthesised by chemists in the pharmaceutical industry. However, the starting point may still be a chemical extracted from a plant.
• New medical drugs have to be tested and trialled before being used to check that they are safe and effective.
• New drugs are extensively tested for toxicity, efficacy and dose.
• Preclinical testing is done in a laboratory using cells, tissues and live animals
• Clinical trials use healthy volunteers and patients:

  • Very low doses of the drug are given at the start of the clinical trial.
  • If the drug is found to be safe, further clinical trials are carried out to find the optimum dose for the drug.
  • In double blind trials, some patients are given a placebo.
• A placebo is a treatment that appears real, but is designed to have no therapeutic benefit