This week’s British Medical Journal has an article “The antibiotic course has had its day,” by Llewelyn et al., that recommends against taking antibiotics for a full standard course. It goes further to challenge the WHO advice to take antibiotics “exactly as prescribed,” and suggests that cessation of symptoms is a better indicator of when to stop. This is welcome, and about time. However the bad advice doctors have given their patients for decades results from ignorance about evolutionary biology. The BMJ article does not use the word “evolution” or the phrase “natural selection.” It does not cite the work of evolutionary biologists who have analyzed this problem for years. Instead, it relies on brute empiricism. When will medicine incorporate sophisticated evolutionary biology so it can avoid making such mistakes?

The article is behind a paywall, but here are choice bits.   “in materials supporting Antibiotic Awareness Week 2016 WHO advised patients to “always complete the full prescription, even if you feel better, because stopping treatment early promotes the growth of drug-resistant bacteria.”  However the article goes on to say, “the idea that stopping antibiotic treatment early encourages antibiotic resistance is not supported by evidence, while taking antibiotics for longer than necessary increases the risk of resistance.” “Outside hospital, where repeated testing may not be feasible, patients might be best advised to stop treatment when they feel better, in direct contradiction of WHO advice. Of note, a recent clinical trial found that using fever resolution to guide stopping antibiotics in community acquired pneumonia halved the average duration of antibiotic treatment without affecting clinical success.”

“The fallacious belief that antibiotic courses should always be completed to minimise resistance is likely to be an important barrier to reducing unnecessary antibiotic use in clinical practice and to developing evidence to guide optimal antibiotic use. The idea is deeply embedded, and both doctors and patients currently regard failure to complete a course of antibiotics as irresponsible behaviour.”

Llewelyn, M. J., Fitzpatrick, J. M., Darwin, E., SarahTonkin-Crine, Gorton, C., Paul, J., … Walker, A. S. (2017). The antibiotic course has had its day. BMJ, 358, j3418.