Study finds no evidence to support antibiotic use for chronic low back pain

By Rebecca Jenkins

Antibiotics should not be used to manage chronic low back pain, an Australian randomised controlled trial suggests.

Previous research investiga­ting antibiotics to treat low back pain had produced conflicting results, the study authors wrote in JAMA Network Open.

In this community-based trial, 170 adults (mean age, 44.4 years) with chronic low back pain and the presence of disc herniation on MRI were randomised to receive either amoxicillin-clavulanic acid 500/125 mg or identical placebo twice daily for 90 days.

At three months and 12 months, researchers found treatment with amoxicillin-clavulanic acid did not result in greater pain reduction than placebo, independent of baseline pain. Prespecified subgroup analysis showed no difference in pain between the groups in people who had Modic (bone) changes detected on MRI.

One participant in each group experienced a serious adverse event that was assessed as possibly related to the interven­­tion. Overall, 34 people (40%) in the antibiotic group and 20 people (23.5%) in the placebo group reported any adverse event.

Senior author Associate Professor Donna Urquhart, from the School of Public Health and Preventive Medicine, Monash University, Melbourne, told Medicine Today there had been interest over the past decade in the idea that low-grade bacterial infection within spinal discs might contribute to low back pain in some patients.

‘Early clinical trials reported substantial benefits from anti­biotic treatment, which gene­r­ated significant interest among clinicians and patients and led to ongoing interest about whether antibiotics could have a role in managing chronic low back pain,’ Professor Urquhart said.

Professor Urquhart noted that a Cochrane Review published earlier this year concluded that antibiotics may provide a small- to-moderate benefit to patients with Modic type 1 changes and disc herniation, but it rated the certainty of that evidence as low.

‘Our study adds to the evi­dence base as one of the largest placebo-controlled trials to examine this question and by evaluating amoxicillin-clavulanic acid, a broad-spectrum antibiotic targeting organisms previously implicated in this hypothesis,’ she said.

First author Professor Flavia Cicuttini, Head of the Musculo­skeletal Unit at Monash Univer­s­ity, said given the lack of benefit, the potential for side effects and the broader public health threat of antimicrobial resistance, the findings did not support anti­­bio­tics for chronic low back pain.

‘For GPs, these results will help guide discussions about treatment options with patients who may have read about antibiotic therapy online or been referred for consideration of this treatment,’ she said.

‘The evidence suggests antibiotics should not be used. The focus should remain on evidence-based approaches to managing chronic low back pain, such as patient education and physical activity.’

JAMA Netw Open 2026; doi: 10.1001/jamanetwork open.2026.12848.