When is the right time to stop taking antibiotics?

Press coverage has picked up on an interesting paper The antibiotic course has had its day published in the British Medical Journal (online 26th July 2017). The paper was of interest to me as I studied antibiotic resistance for my PhD, and this topic was also the theme of (to date) my only appearance on TV news.


As anyone who has ever been prescribed antibiotics ought to know, current clinical practice from the World Health Organisation and others recommends completion of the course (often 7 days), even if the patient feels better sooner. The justification for this strategy has been concern that premature ending of treatment might allow the disease-causing bacteria to recover and continue to wreak havoc, possibly in a newly-resistant manner.

In the new paper, Martin Llewelyn (Brighton and Sussex Medical School) and colleagues from a number of institutions in South-East England question the basis of this recommendation. Whereas the link between exposure to antibacterials and the development of resistance is well documented, these authors wondered about the origins of the original advice. They suggest that the requirement to “complete the course” probably stands on little more than the anecdotal experience of some of the antibiotic pioneers.

In the very earliest clinical application of pencillin, when the drug was still experimental and in very short supply, the patient showed an encouraging initial response, but died when the stocks were exhausted. That work, conducted by Howard Florey, contributed towards his receipt of the Nobel Prize in 1945. It was the speech of his co-recipient Alexander Fleming that the present paper considers to have had the greatest influence on the demand to complete the course. Fleming is quoted as saying “If you use penicillin, use enough!”

Llewelyn and colleagues suggest that fear of under-treatment was, in those early days, a greater concern to the researchers than the development of resistance. Even if that view was excusable at the time, we now live in a very different era, with warranted fears that the emergence of multiply-resistant strains is outpacing the discovery of new antibacterials. (I would add that there is a distinction between the risk of resistance-development arising from exposure to a sub-therapeutic dose of a drug and short-term exposure to an appropriate therapeutic quantity.)

The authors note that there have been a number of recent policy interventions to avoid clinicians starting unnecessary antibiotic treatments, but there have been few studies aimed at stopping treatments more promptly. Thus, the main thrust of the present opinion piece is an urgent call for randomised controlled trials to be conducted to investigate whether shortening of drug regimes will have any adverse effects.

As part of this analysis, there also needs to be more careful reflection of the nuances of therapy. Just as there is a move away from “one size fits all” approaches to other kinds of therapy, so too there needs to be greater emphasis placed on the differences between patients and/or between different infective agents

Reflection: I found this an interesting and thought-provoking read. It serves as a reminder that many existing practises taken as *the* way to do things actually derive from an era where the underlying justification may have been anecdotal or non-existent. Clearly we cannot routinely go back to the primary studies and check for ourselves whether they are warranted; if we did so we’d never have time to make new observations! Nevertheless there are times when a fresh re-examination of the evidence is appropriate, and I believe the present authors have highlighted a need for re-consideration of the advice governing the duration of antibiotic treatments.

1 Comment

  1. […] further coverage see my Journal of the Left-Handed Biochemist post on the paper, and this article from the Daily […]

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