GP surgeries with doctors who have training in complementary and alternative medicines appear less likely to prescribe antibiotics to patients, a study suggests.

Researchers say the finding, published in the journal BMJ Open, could hold the key to reducing over-prescribing of the drugs.

Experts have previously warned that resistance to antimicrobial drugs could cause a bigger threat to mankind than cancer. Cuts in antibiotic use have been shown to be associated with a reduction in some resistance.

In the UK, 74% of antibiotics are prescribed in primary care. Prescribing rates between GPs vary due to factors including different views on medicalisation, guidelines between countries and use of complementary and alternative medicine.

Researchers from the UK, Germany and the Netherlands, led by the University of Bristol, used NHS Digital monthly prescribing data for 2016 from 7,274 GP surgeries.

This was compared with nine practices that had GPs with training in integrative medicine, looking at overall prescribing of antibiotics and prescribing of these drugs for respiratory tract infections and urinary tract infections.

Practices with GPs who had additional training in integrative medicine had significantly lower antibiotic prescribing rates than those with conventional GPs, the study found.

Doctors with the additional training also prescribed noticeably fewer antibiotics for patients with respiratory tract infections, though there was no difference when it came to patients with urinary tract infections.

The authors said: “For the majority of respiratory tract infections, it is recommended that antibiotics should be avoided or delayed, so that this is an area where the desired reduction in prescribing could take place.

“Additional treatment strategies for common primary care infections used by practices with GPs trained in integrative medicine should be explored to see if they could be used to assist in the fight against antimicrobial resistance.”

The authors acknowledged that their results were limited by the lack of data of number of consultations, individual GP characteristics, individual deprivation scores and continuum of care.

The pool of practices with GPs trained in integrative medicine was small. This is because accessing integrative medicine and complementary and alternative therapies within the NHS in general practice is very limited, the researchers said.

Provisions for integrative medicine and complementary and alternative therapies are almost exclusively private in the UK, they added.

But they said the difference seen in antibiotic prescribing rates seen at practices with GPs trained in integrative medicine warranted further study.

This difference could be explained by patients seen by GPs trained in integrative medicine being less keen on receiving antibiotics, or the practices having other avenues to offer patients, they added.

Prescribing rates by practices with GPs trained in integrative medicine were in line with current national guidance aimed at reducing antibiotic usage, the research team said.