• Question: @sarah @ nike @ nicola @ kirsty @ austin what chemicals are in antibiotics

    Asked by zaman123 to Austin, Kirsty, Nicola, Nike, Sarah on 19 Jun 2012.
    • Photo: Austin Elliott

      Austin Elliott answered on 19 Jun 2012:

      An antibiotic is a chemical – usually a chemical substance with a complicated structure originally made by a living organism (a kind of mould in the case of penicillin), though all antibiotics in use now are synthetic (made by scientists).. Basically, once a natural chemical is discovered that has nasty-bacteria-killing properties, the chemists go to work making lots of slightly different versions of the molecule that have more useful properties. All antibiotics work in one of two ways, either by killing bacteria, or by stopping the bacteria from multiplying.

      A famous example of ‘making better antibiotics’ is that the original penicillins had to be given by a daily injection (ouch!) – the reason was that they were broken down by acid, so if you took them by mouth then the acid in your stomach destroyed them before they could be absorbed and help you fight the infection.So the chemists made new versions that were ‘acid-resistant’, and now we have penicillins we can take as tablets.

      Most antibiotic tablets only contain one type of antibiotic molecule, though sometimes they have two together. Antibiotics can be divided into ‘classes’ – groups of similar molecules that work in similar ways. There is an explanation on Wikipedia, though it might be a bit complicated.

    • Photo: Kirsty Ross

      Kirsty Ross answered on 19 Jun 2012:

      In addition to what Austin said, most antibiotics are originally discovered in microorganisms that live and compete with one another in the soil. The vast majority of antibiotics were discovered in the 50s and 60s. There has been a significant decrease in the number of antibiotics being discovered and tweaked for new purposes, as the drug development companies didn’t think there was a lot of profit in it. It takes a LONG time and a lot of money to develop a new drug for humans, and antibiotics are only taken for a short time so that there was less money to be made to cover the costs of development.

      As the number of discovered antibiotics has dwindled, the bacteria that they treat have continued to evolve to be resistant to the current drugs. This has led to the rise of methicillin resistant Staphlyococcus aureus (or MRSA), extremely resistant TB and an almost untreatable Neisseria gonorrhoeae. This is becoming a real problem, and it is why it is so important for patients to finish their antibiotic treatment, even when you are feeling better. If you don’t, there may still be bacteria left that have seen the antibiotic, changed their DNA (and mutated) and will be resistant the next time they cause disease.

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