Bristol study highlights how reduced antibiotic prescriptions can help reduce antibiotic resistance

Colin Garner ANTRUK announcements, Learn more

Our charity is increasingly concerned that antibiotic resistant bacterial infections could be forgotten because of the current focus on the COVID-19 pandemic. While the world is focuses on the viral pandemic, the fight against antibiotic resistance cannot be ignored. The public are increasingly visiting our website to learn more about antibiotic resistant infections.

Antibiotic resistance is driven by the overuse, inappropriate use and misuse of antibiotics. Antibiotic Research UK has as part of its mission education programmes centred on antibiotic prescribing. We keep a watching brief on research that provides an evidence base for our activities.

New Bristol University study

Colin Garner, Chief Executive of Antibiotic Research UK, says “A new study from Bristol University suggests that changes to antibiotic prescriptions can have an impact on antibiotic resistance within as little as three months of making the change. It also highlights the complexity of the topic and the desperate need for further high-quality research to help us understand exactly what we are dealing with and what needs to be done.”

The study (Hammond et al, 2020) was carried out by researchers at Bristol University. It highlighted an interesting link between antibiotic prescriptions and resistant bacteria. Efforts to reduce the number of antibiotics dispensed by GPs and in hospitals were linked to the rates of infection with bacteria that are resistant to some of those antibiotics.

The study involved mathematical analysis of the rate of infection with specific bacteria and the dispensing rate of antibiotics. The data was taken between 2013 and 2016 in an area of South West England that covers around 1.5 million patients. The results were adjusted for patient age, deprivation and rurality, meaning that those factors have been taken into consideration and will not have affected the results. It is worth noting that these results are reflective of data gathered in pre-COVID times.

The results

The results showed that the national trend of a reduction in the prescription of antibiotics during that period was reflected in the local area.

  • Amoxicillin fell 14%
  • Cefalexin 20%
  • Ciprofloxacin 24%
  • Co-amoxiclav 49%
  • Trimethoprim 8%

Nitrofurantoin prescription levels increased by 7% during this time. This is possibly due to high levels of trimethoprim-resistant urinary tract infections. Nitrofurantoin became the first-line antibiotic for those with this condition).

Reductions in three of these antibiotics (amoxicillin, ciprofloxacin and trimethoprim) were associated with reductions in antibiotic-resistance to those treatments. This was true of data in the same quarter that the reduction was measured, as well as the subsequent quarter for two of those treatments.

However, reductions in cefalexin and co-amoxiclav prescribing were associated with increased resistance to those two drugs within the same and the following quarter. Although, the authors do state that this could be due to ‘residual confounding’ of the data. Interestingly, increased dispensing of nitrofurantoin was associated with reduced resistance to trimethoprim and had no effect on resistance to nitrofurantoin.

The authors concluded that these results show that benefits and unexpected harm resulting from reducing the levels of antibiotic prescriptions. They assert that randomised controlled trials are therefore the best approach for future research.

Antibiotic Research UK is the only charity in the UK that is dedicated to fighting back against antibiotic resistant infections. If you can support our work, you’ll help us to save modern medicine for everyone.

Find out more

There are many common misconceptions around antibiotic resistance. For example, people believe it’s the human body that becomes resistant to antibiotic treatments. It is the harmful bacteria (which make us sick) that become resistant to the antibiotics.

If you’d like to know more, read our information on antibiotic-resistant infections and bacteria, or sign up for our newsletter.