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Fighting Disease - Drugs
Painkillers don't actually tackle the cause of the illness. They only relieve pain by reducing the
symptoms. Some examples would be aspirin, paracetamol and ibuprofen.
Antibiotics can actually kill or prevent the growth of the bacteria causing the illness. They do not
work on viruses because viruses reproduce inside your own body cells, so it's really difficult to
produce a drug that kills a virus without damaging your own cells.
Bacteria can become resistant to antibiotics and I'll explain how below. I would memorise this as it
could come up as a six mark question in the exam. Even if it's not a six mark question, they are likely
to ask you something about it.
Bacteria can mutate. Sometimes these mutations can cause them to become resistant to a certain
type of antibiotic. If you have an infection, some of the bacteria might be resistant to the antibiotic.
This means when you treat the infection, only the non-resistant strain will be killed. The individual
resistant strain will survive and reproduce, increasing the population, which is an example of natural
selection. This resistant strain could cause a serious infection that can't be treated by antibiotics (e.g.
MRSA). To slow down the rate of development of resistant strains of bacteria, doctors can avoid
over prescribing antibiotics and we should always finish the antibiotics given.