By Jean Balchin 27/07/2017

The commonly held belief that patients should “complete the course” of antibiotics to avoid antibiotic resistance is not backed by evidence and should be dropped, argue experts in The BMJ (The British Medical Journal) today.

According to Professor Martin Llewelyn at Brighton and Sussex Medical School and colleagues, patients are actually put at unnecessary risk from antibiotic resistance when treatment is given for longer than necessary, not when it is stopped early. It’s time for policy makers, educators, and doctors to drop this message and state that this was not evidence-based and is incorrect.

Antibiotic-resistant bacteria

Antibiotics, also known as antibacterials, are medications that destroy or slow down the growth of bacteria. They include a range of powerful drugs and are used to treat diseases caused by bacteria. “Antibiotics are vital to modern medicine” yet, “antibiotic resistance is a global, urgent threat to human health.” According to the World Health Organisation, “antibiotic resistance occurs when bacteria change in response to the use of these medicines.” Humans or animals do not become antibiotic-resistant; bacteria do. These antibiotic-resistant bacteria may infect humans and animals, and the infections they cause are harder to treat than those caused by non-resistant bacteria.

Public communications

Public communication about antibiotics frequently emphasises that patients who fail to complete prescribed antibiotic courses put themselves and others at risk of antibiotic resistance. The notion that topping antibiotic treatment early encourages antibiotic resistance is not supported by evidence however. Indeed, taking antibiotics for longer than necessary increases the risk of resistance, explain the authors.

Taking antibiotics for longer than necessary increases the risk of resistance.

This advice has been embraced over the years because it is simple and unambiguous, and the behaviour it advocates is clearly defined and easy to carry out, the authors of the study suggest. However, there is evidence to suggest that stopping antibiotics sooner is a safe and effective way to reduce antibiotic overuse. There are notable exceptions for some types of antibiotic, such as those used to treat tuberculosis, a rare multi-system genetic disease that causes benign tumours to grow in the brain and on other vital organs such as the kidneys, heart, liver, eyes, lungs, and skin.

However, one of the most fundamental and widespread medication beliefs people have is that we should take as little medication as necessary. Unnecessarily completing a course of antibiotics defies this belief. The study argues that the public should also be encouraged to recognise that antibiotics are a precious and finite natural resource that should be conserved by tailoring treatment duration for individual patients. Evidently, it is imperative that clinical trials be conducted to determine the most effective strategies for optimising duration of antibiotic treatment.