Medicines

When we feel ill we take medicines. These medicines may fight the invading germs or they may just make us feel better while our body does the fighting.

	Paracetamal is a pain killer. It has no effect on the germs but will help to keep any fever down and relieve aches and pains.
	Penicillin is an antibiotic. If you have a bacterial infection these drugs will fight them in the same way as our antibodies do.
	Because viruses reproduce inside cells they are much harder to fight with drugs without damaging the cells that they inhabit. If you have a viral infection there is not much that the doctor can give to help you.

Imagine there are millions of a certain kind of bacteria in a room and we try to kill them with an antibiotic. A very small number of them might not be killed because they are not affected by this antibiotic. The ones that survive will then multiply and the bacteria that come from them will be resistant to this antibiotic. For this reason we should not use antibiotics unless they are really necessary.

MRSA is a bacteria which is in the news a lot now. It has become resistant to most of the drugs that are available to fight infection. It is often referred to as a superbug.

REMEMBER

• Some medicines, including painkillers, help to relieve the symptoms of infectious disease, but do not kill the pathogens.
• Antibiotics, including penicillin, are medicines that help to cure bacterial disease by killing infective bacteria inside the body.
Antibiotics cannot be used to kill viral pathogens, which live and reproduce inside cells. It is difficult to develop drugs which kill viruses without also damaging the bodies tissues.
• Many strains of bacteria, including MRSA, have developed resistance to antibiotics as a result of natural selection. To prevent further resistance arising it is important to avoid over-use of antibiotics.