| How was Penicillin Found? | Sir Alexander Fleming discovered penicillin from the Penicillium mould. |
| Plant Extracts of Drugs | ASPIRIN:
Ancient Greeks used willow bark to cure fevers and pains
- It was later discovered that the active ingredient was salicylic acid
- Salicylic acid was later modified into aspirin which is less irritating to the stomach
DIGITALIS:
- Heart drug
- Extracted from foxgloves |
| Thalidomide (Discovery of Drugs) | HISTORICALLY:
- Thalidomide was developed as a sleeping pill and was also thought to be useful for easing morning sickness in pregnant women
- Caused unexpected serious damage to unborn babies in 1950-60's (especially if it had been taken in the first 4-8 weeks of pregnancy). More than 10,000 babies were affected around the world. Also caused babies legs/arms to be very short.
- As a result of this disaster, thalidomide was banned & drug testing was also made more rigorous than before
TODAY:
-Thalidomide is now used as a treatment for leprosy and bone cancer
- Its use is heavily regulated to prevent a repeat of the problems it caused in the last century |
| Why are New Medical Drugs Tested? | To ensure that they work, and are safe, before they can be prescribed. They are tested for:
1) Safety - This is important as some drugs are toxic, and have other side effects that might be harmful to people
2) Effectiveness - This is also known as efficacy, and checks how well the drug cures the disease, or improves symptoms
3) Dosage - This varies, and has to be closely controlled, as too high a concentration might be toxic |
| What are the 3 main Stages of Drug Testing? | 1) STAGE 1: Drugs are tested in Laboratories using computer models and skin cells grown using human stem cells. Tests: efficacy and possible side effects. Many substances fail this first test of a preclinical drug trial because they damage cells or do not seem to work
2) STAGE 2: New medicines tested on animals (In UK), illegal to test cosmetics and tobacco products on animals. Typically involves giving a known amount of substance and monitoring carefully for any side-effects
3) STAGE 3: Human clinical trials. Tested on healthy volunteers to check that they are safe, then tested on people with the illness to ensure that they are safe and that they work. Low doses of the drug are used initially, and if this is safe the dosage increases until the optimum dosage is identified |
