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Taking Antibiotics
When
To Take Antibiotics (And When To Avoid Them)
Matthew
Cooper
Antibiotic-resistant
superbugs are on the rise and we're being urged to forgo antibiotics wherever
possible to limit their spread.
But serious bacterial
infections can only be dealt with effectively using these drugs. So when should
you take antibiotics?
The easy answer, of
course, is when your doctor tells you to. But there's more to it than that.
We know that rates of
bacterial resistance track antibiotic usage rates.
So, as a community,
the more we take these drugs, the more likely we are to have superbugs down the
line. And Australia may face a bleak future in these terms.
Antibiotic myths and
facts
The Australian
government's 2015-2019 National Antimicrobial Resistance Strategy highlighted
some interesting, if somewhat disturbing, facts:
A 2014 poll of
Australian workers showed 65% believed taking antibiotics would help them
recover faster from a cold or flu
20% of people expect
antibiotics for viral infections, such as a cold or the flu
Nearly 60% of GPs
surveyed would prescribe antibiotics to meet patient demands or expectations
surgical prophylaxis
(giving antibiotics before or during surgery to minimise the risk of infection)
is used in 41% of cases, which is much higher than the recommended best
practice of less than 5%
Clearly, we still
don't understand that antibiotics won't kill viruses responsible for the flu
and many common colds.
And a majority of
doctors take a seemingly lackadaisical approach to antibiotic stewardship. It's
no surprise then that the 2013 National Antimicrobial Prescribing Survey showed
30% of antibiotic prescriptions were inappropriate.
Antibiotics are
amazing drugs that can prevent serious harm and stop infections becoming fatal.
They're often used for:
lung infections,
which include bacterial pneumonia and pertussis (whooping cough)
urinary and genital
infections, some of which are sexually transmitted
eye infections
(conjunctivitis)
ear, nose and throat
infections (otitis, sinusitis and pharyngitis)
skin infections (from
impetigo in schoolchildren through to more serious diabetic foot ulcers)
diarrhoea and more
serious gut infections, such as those caused by Clostridium difficile
In general, a patient
will be given antibiotics if her symptoms are severe (a high fever or skin
rash, for instance, or inflammation spreading around an infection site); she
has a higher risk of complications (such as an elderly patient with suspected
pneumonia); or if the infection is persistent.
Getting it right
To prescribe, the
doctor makes an educated guess as to what may be causing the infection. This is
based on knowledge of what type of bacteria are normally found in these cases
and, if available, the patient's history.
But she doesn't know
exactly what type of bug is causing the infection.
In the absence of an
accurate diagnosis, as well as to minimise potential risk to the patient, a
broad-spectrum antibiotic is used to "cover as many bases" as
possible.
Until we can develop
point-of-care technology that can identify a bug on demand, such broad-spectrum
drugs (the grenade approach to bacteria) are a better option for doctors than
targeted specific drugs (a sniper against superbugs).
But the latter is the
better long-term option for the patient and the community, although it may not
always work.
One key problem with
broad-spectrum "grenade" antibiotics is that they can cause
collateral damage by killing a lot of good bacteria.
We now know that we
have about a kilogram and a half of good bacteria in our guts that help us
digest food. They also "crowd out" potential nasty infections caused
by bad bacteria.
There are cases where
patients on antibiotics end up with diarrhoea, thrush (a vaginal infection
caused by Candida that goes wild when protective bacteria are wiped out), or
nasty infections, such as Clostridium difficile, that can lead to severe
colitis.
And it gets worse: a
recent Danish study that followed more than a million patients found an
association between frequency of antibiotic use and Type II diabetes,
generating considerable media interest.
It found people who
received more than four courses of the drugs over 15 years were 53% more likely
to develop diabetes.
Caveats and
conclusion
Of course, there's
the cause-effect corollary. People who were already heading towards the disease
may simply have been less healthy, more prone to infection, and hence had more
visits to the doctor to get antibiotics.
The study showed an
association between antibiotics and diabetes, not causality.
So where do we stand
now? Remember bacterial infections can kill, and antibiotics save lives, so if
you're really feeling crook, go to your doctor and take her advice.
But also think twice.
If you have a bad cold or think you have the flu, remember this may be due to a
viral infection. And using antibiotics could do you more harm than good in the
longer term.
The real game changer
in all of this will be a "tricorder" diagnostic that can identify a
bug on site. With such a technology, a doctor could prescribe the right drug,
the first time, in time. So be sensible about using antibiotics and let's keep
our eyes on this prize.
Matthew
Cooper,
Prof. Institute for Molecular Bioscience, The University of Queensland
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