B3 Fighting Disease - Drugs (page 48) Flashcards
Some Drugs can relieve symptoms, what can other drugs do?
cure the problem.
What are Painkillers (e.g. asprin)?
they are drugs that can relieve pain.
What do Painkiller do?
they don’t actually tackle the cause of the disease or kill pathogens, they just help to reduce the symptoms.
(other drugs do a similar kind of thing - reduce the symptoms without tackling the underlying cause. for example - lots of “cold remedies” don’t actually cure colds.
What are Antibiotics (e.g. Penicillin)?
Antibiotics work differently to pain killers, they actually kill (or prevent the growth of) the bacteria causing the problem without killing your own body cells.
(Different antibiotics kill different types of bacteria, so it’s important to be treated with the right one).
What don’t Antibiotics destroy, and why?
they don’t destroy viruses (e.g. flu or cold viruses).
Viruses reproduce using your body cells, which makes it very difficult to devlop drugs that destroy just the virus without killing the body’s cells.
How has antibiotics helped over the years?
antibiotics has greatly reduced the number of deaths from communicable diseases caused by bacteria.
Can Bacteria become resistant to antibiotics, and why?
Yes.
Bacteria can mutate (change). This can cause them to be resistant to (not killed by) an antibiotic.
If you have an infection, why could an antibiotic not work?
some of the bacteria might be resistant to antibiotics.
This means that when you treat the infection, only the non-resistant strains of bacteria will be killed.
What happens if antibiotics don’t kill resistant bacteria?
the resistant bacteria will survive and reproduce, and the population of the resistant strain will increase. (This is an example of natural selection (see page 76)).
What can a resistant strain of bacteria cause?
it could cause a serious infection that can’t be treated by antibiotics.
E.g. MRSA (meticillin-resistans Staphylococcus aureus) causes serious wound infections and is resistant to the powerful antibiotic Meticilln).
How can we slow down the rate of development of resistant strains of Bacteria?
It’s important for doctors to avoid over-prescribing antibiotics. So you won’t get them for a sore throat, only for something more serious.
Why is it important that you finish the whole course of antibiotics, and don’t just stop once you feel better?
To prevent relapse of infection and the development of antibiotic resistance.
Where did many drugs orginally come from and why?
Plants, as plants produce a variety of chemicals to defend themselves against pests and pathogens.
A lot of our current medicines were discovered by studing plants used in traditional cures, give some examples?
Some of the chemicals from our plants can be used as drugs to treat human diseases, or relieve symptoms.
e.g. Asprin is used as a painkiller and to lower fever. It was developed from a chemical found in Willows.
Digitalis is used to treat heart conditions. It was developed from a chemical found in Foxgloves.
In the past, Some drugs was extracted from Microorganisms. Give example of what Alexander Fleming found?
Alexander Fleming was clearing out some Petri dishes containing bacteria. He noticed that one of the dishes of bacteria also had mould on it and the area around the mould was free of the bacteria.
He found that the mould (called Penicillium Notatum) on the Petri dish was producing a substance that killed the bacteria - this substance was Penicillin.
