Questions over advice to finish courses of antibiotics

"Should you finish a course of antibiotics?" asks BBC Online. The question is prompted by a new review suggesting concerns around antibiotic treatment are driven by fears of under-treatment, when we should instead be concerned about over-use.

Patients have always been advised to finish their course of antibiotics even if they're feeling better. The reasons given are that this will stop the infection from returning, as well as reduce the risk of the bacteria becoming resistant to the antibiotics.

The researchers behind this review challenge these established ideas by suggesting that shortening the course of antibiotic treatment could be just as effective and that "finishing the course" could actually be making the problem of antibiotic resistance worse.

As interesting as this review is, it's important to be aware of the type of research this was. It is a narrative review, which means it was a review that discusses evidence about a particular topic.

It is unclear how the authors picked the evidence that informed this piece. Reviews of this type are always vulnerable to accusations of "cherry-picking", where researchers include evidence that supports their argument while ignoring evidence that doesn't.

Guidelines on prescribing are not set in stone and are constantly being revised. It could be the case that this review leads to a change in recommendations. But until any changes are announced, it is a good idea to take your antibiotics as prescribed, even if you are feeling better.

Who produced this review?

This narrative review was written by researchers from several UK institutions, including Brighton and Sussex Medical School, the University of Oxford and the University of Southampton. It was published in the peer-reviewed British Medical Journal and is free to read online (PDF, 1Mb).

Generally the UK media's coverage was accurate and balanced. The majority of reporting referred to the review as an "opinion piece" and highlighted the importance of people continuing to follow doctors' advice to complete a prescribed antibiotic course.

What is antibiotic resistance?

Antibiotic resistance can build up after bacteria have become repeatedly exposed to antibiotics. The bacteria change or adapt so they are no longer affected by the antibiotic. This renders antibiotics ineffective against infections they were previously able to treat.

It has been widely accepted that stopping antibiotic treatment early encourages bacteria to develop antibiotic resistance. As a result, current medical advice is to finish taking a prescribed course of antibiotics as recommended by a healthcare professional, even if you start to feel better.

What does this review say?

This review challenges current medical advice by suggesting that concerns around antibiotic treatment are driven by fears of "under-treatment", where the course of antibiotics doesn't last long enough to clear any infection, when the concern should be more about over-use.

The authors of the piece make the point that when antibiotics were first used during the 1940s, there was little awareness of the problems of antibiotic resistance, so the concept of "over-use" was never even considered.

In summary, the review raises the following points:

• Only a limited number of studies have investigated the minimum treatment period needed for antibiotics to be effective. There is little or poor evidence to support the idea that shorter treatments would lead to an increased risk of antibiotic resistance or treatment failure. The authors do, however, acknowledge that some trials have found that for certain conditions, shorter treatment has compromised recovery.
• Always prescribing a fixed number of days for a course of antibiotics can potentially overlook individual patient characteristics, such as the fact that some patients may respond differently to the antibiotics. For example, a patient's previous antibiotic exposure is not necessarily considered.
• It is difficult to test the theory that a shorter antibiotic course may be just as effective as a longer one, because the importance of completing a full course of antibiotic treatment is so deeply embedded in both doctors and patients.
• Public health education around antibiotics needs to highlight that antibiotic resistance is the result of the overuse of antibiotics by patients, and that it cannot be prevented by completing a course. Simpler messages should be issued, such as, "stop when you feel better."

What evidence is this based on?

The researchers of this narrative review say they have used data from randomised controlled trials (RCTs) and observational cohort studies to inform the points made. However, there is no clear methodology so we don't know how the evidence was chosen and whether it was systematic in manner. So the reviewers run the risk of being accused of picking the evidence to support their hypothesis.

When testing a hypothesis like this, a systematic review or meta-analyses would have been the best approach to reviewing the evidence.

Conclusions

This narrative review challenges current medical advice that patients should complete their course of antibiotics, by suggesting that concerns around antibiotic treatment are driven by fears of under treatment, when we should instead be concerned about over use.

Professor Peter Openshaw, President of the British Society for Immunology and Professor of Experimental Medicine at Imperial College London commented:

"It could be that antibiotics should be used only to reduce the bacterial burden to a level that can be coped with by the person's own immune system. In many previously healthy patients with acute infections, letting them stop the antibiotics once they feel better has considerable appeal. However, there are clearly circumstances where antibiotics should be given for extended periods."

"Ideally, there should be clinical trials to support the duration of therapy but in the meantime it should be up to the prescriber to recommend how long to continue treatment."

Professor Mark Woolhouse, Professor of Infectious Disease Epidemiology at the University of Edinburgh, said:

"The article underlines that educating not only patients but also doctors is essential to changing current prescribing practices. It is very clear that prescribing practices do need to change; there is every indication that current volumes of antibiotic usage are too high to be sustainable. We need to start to use antibiotics more wisely before it's too late. The longer we delay, the worse the resistance problem will become."

This review raises some interesting points and the guidelines around antibiotic treatments may change in the future. However, for now it's best to stick with current advice to complete the full antibiotic course as prescribed.