Thanks to antibiotics, some of
the most widespread and deadly diseases have been conquered. But using
them too freely may be detrimental to health. So how do they work and
when do you really need them?
Around one in every six prescriptions issued in the UK is for
antibiotics. Since the first antibiotic, penicillin, was introduced in
the 1940s, these drugs have saved countless lives and have been
some of the most dramatic advances in modern medicine.
Diseases that were once fatal, like pneumonia, tuberculosis, syphilis,
gonorrhoea, bacterial meningitis (inflammation of the brain), and
typhoid, can now be treated and cured with antibiotics. Relatively
trivial ailments, such as tonsillitis, cystitis and conjunctivitis,
often respond to antibiotics too. However, useful though they are,
antibiotics should never be used lightly.
From the moment we are born, each of us is constantly exposed to
bacteria. They are present in food, plants, the soil, the air we breathe
and in our own bodies.
Not all bacteria are harmful, but normally our immune systems protect
us against those which are. But if our immune defences are low, and
bacteria normally present in the body move to a different site or
harmful bacteria invade our body from outside, illness can occur.
Antibiotics are, quite simply, drugs that kill bacteria. They have no
effect on viruses, which is why they are not prescribed for the common
cold, flu or chicken pox.
Some types of antibiotics act by interfering with the chemicals that
bacteria need to form their cell walls. Others hijack their ability to
multiply and reproduce. Their most remarkable action is their ability to
be selective. In other words, a particular antibiotic drug only kills or
maims specific types of bacteria, leaving others unharmed.
CHOOSING THE DRUG
There are many different types of antibiotics so your doctor will try to
tailor the drug to your illness. Bronchitis, for example, may be caused
by different bacteria, each needing a particular antibiotic.
Your doctor may perform tests to identify the particular organism
that is causing your infection before prescribing. Sometimes he may rely
on his medical knowledge to prescribe the most likely antibiotic.
Alternatively, he may prescribe a 'broad spectrum' antibiotic - one that
is effective against a large number of organisms - before switching to a
specific type once the infection has been identified.
One of the biggest problems with the widespread use of antibiotics is
that strains of bacteria develop which are resistant to antibiotics.
This happens when the bacteria produce mechanisms of growth and
reproduction that can't be stemmed by antibiotics, or release chemicals
that deactivate them.
Resistance may occur if you have had to take antibiotics for a long
period, if the drug has not worked, if you fail to complete a full
course of the drugs or if you don't take them regularly. These resistant
strains may then be passed to other people. This is why it's important
to take antibiotics as prescribed.
Antibiotics are usually safe, though they can cause side-effects.
Some provoke allergic reactions, usually in the form of rashes or a
swollen face and throat. If you have had such a reaction before, be sure
to mention this to your doctor if he is planning to prescribe
THE THRUSH THREAT
Prolonged courses of antibiotics can also disrupt normal bacterial
activity in the body leading to the growth of candida (thrush), a yeast
that is normally kept in check by bacteria in the mouth, the vagina or
bowel. Other temporary side-effects may include loss of balance,
deafness, indigestion, and diarrhoea. Some antibiotics can also promote
the development of antibiotic-resistant bacteria in the bowel, causing
violent bloody diarrhoea, a serious and potentially fatal side-effect.
If an antibiotic is having a persistent and worrying side-effect, seek
medical help without delay.