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Study proposes antibiotics as possible new treatment for some types of chronic low back pain

BMJ 2013; 346 doi: http://dx.doi.org/10.1136/bmj.f2988 (Published 09 May 2013) Cite this as: BMJ 2013;346:f2988
  1. Jacqui Wise
  1. 1London

Up to 40% of patients with chronic low back pain that could benefit from surgery have a bacterial infection that could be treated simply and cheaply with antibiotics, research has found.

The first of two studies in the European Spine Journal found Propionibacterium acnes, an anaerobic bacteria, in 43% of patients undergoing primary surgery for lumbar disc herniation.1 Hanne Albert and colleagues at the University of Southern Denmark also found that new bone oedema (Modic type 1 changes) developed in adjacent vertebrae of 80% of discs infected with the anaerobic bacteria.

Previous studies had shown that Modic changes were six times as common in people with low back pain as in the general population. This was mostly thought to be the result of mechanical reasons, but it was known that under some circumstances infections played a role. Conventional treatments for back pain such as exercises, injections, and manipulation were ineffective in patients with Modic changes.

The study of 61 patients found a highly significant association between presence of the anaerobic bacteria in nuclear tissue of discs and Modic change (P=0.0038), with an odds ratio of 5.6 (95% confidence interval 1.5 to 22). The researchers said that this discovery merited the establishment of a new disease category: Modic related low back pain.

One key question was whether the bacteria found in the nuclear material is indicative of an infection or possibly a result of intraoperative contamination. In an accompanying editorial Max Aebi, editor in chief of the European Spine Journal, said that the authors give a plausible answer that contamination was highly improbable. “Nevertheless, further research is necessary to show what exactly happens in patients with disc herniation who develop Modic change 1 and low back pain and who have not been operated on,” he added.2

In the second study, also in the European Spine Journal and led by Albert, the researchers found that a long course of antibiotic treatment was more effective than placebo in patients with chronic low back pain associated with vertebral bone oedema.3 The double blind, randomised controlled trial involved 162 patients who had chronic back pain of longer than six months after a previous disc herniation and who had Modic type 1 changes in the vertebrae that could be seen on magnetic resonance imaging. The patients were randomised to receive either 100 days of antibiotic treatment with amoxicillin with clavulanic acid or placebo and were evaluated at baseline, at the end of the treatment period, and after one year. Four patients stopped treatment, mainly because of gastrointestinal side effects.

The study, funded by six Danish foundations and the Danish Rheumatism Association, found that 80% of patients who received the antibiotic were significantly better able to function after one year, had less lower back pain, less leg pain, and fewer days off work than patients in the placebo group. The whole course of treatment with the antibiotic costs just £114 (€135; $180).

Propionibaterium acnes normally live in hair follicles, in acne, or on the gums, but the bacteria can pass into the blood stream through teeth brushing. They usually pose no threat as they circulate around the body, but when a person has a slipped disc the body grows fresh blood vessels that reach into the soft disc to repair the tissue. This gives the bacteria a route into the disc, where they can thrive. As the bacteria grow they cause inflammation around the disc and release propionic acid, which can irritate nerves.

Commenting on the research, Peter Hamlyn, consultant neurological and spinal surgeon at the Institute of Sports Exercise and Health, University College London, said, “It’s a paradigm shift in the way we view and treat chronic low back pain—in the same way as the discovery of Helicobacter pylori brought about a shift in how we treat ulcers. We will have to rewrite the textbooks.”

Albert and Hamlyn are board members of the MAST (Modic antibiotics spine therapy) medical academy, which promotes information and training for health professionals and patients in Modic change and chronic lower back pain (www.mastmedical.com).

Hamlyn added that getting patients to comply with 100 days of antibiotic treatment may be a problem. “It won’t be suitable for everyone with chronic lower back pain, but for those severe cases which show up positive on an MRI [magnetic resonance imaging] scan then it is a lot better alternative than carrying out a big operation. We need to change practice now,” he said.

However, Jonathan Johnson, a spinal surgeon and emeritus consultant at Imperial College London, said. “It is an interesting concept, but the work needs to be repeated in a series of patients. There may be something in it, but everyone shouldn’t be rushing to the chemist now. These were a highly selected group of patients.”

He added, “There are side effects from taking antibiotics for three months, as shown by the fact that some patients withdrew from the trial because of chronic diarrhoea. Plus there is the risk of antibiotic resistance.”

Notes

Cite this as: BMJ 2013;346:f2988

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