Can Methylene Blue Injections Treat Low Back Pain?

A study announced in Trials will examine whether intradiscal methylene blue injection (IMBI) could be effective in treating low back pain (LBP). The findings could lead to a new treatment for LBP -- a widespread malady that is a notoriously difficult clinical challenge.

The study is a repeat of 2010 research showing promise for IMBI that was published in Pain. That study showed significant potential for the treatment, which was effective in alleviating pain in 89% of treated patients. Despite the success of the method demonstrated in that study -- which showed good results and was safe, effective, and minimally invasive -- IMBI hasn’t been the subject of a great deal of clinical research since.

For patients suffering from intractable discogenic LBP, there are few evidence-based effective treatment options available. Some clinicians believe IMBI works by destroying small nerve fibers that have overgrown in the intervertebral disc. “Treatment of discogenic chronic low back pain remains controversial. Patients who do not respond to conservative therapy may undergo various treatments, varying from interventional chronic pain treatment to fusion surgery, generally with variable and unpredictable results,” the researchers observed.

For the current study, consecutive discogenic low back pain patients referred to four specialized pain treatment facilities are being screened for eligibility. Participants will be randomized into two groups. The treatment group will receive an intradiscal injection with methylene blue, lidocaine, and contrast, and the control group will receive intradiscal isotonic saline with lidocaine and contrast. Main outcome measures are pain at the 6-month follow-up, patient’s global impression of change, cost-effectiveness, quality of life, disability, and analgesic intake.

Interestingly, the study will also measure the potential impacts of the treatment on costs--including both the cost of the treatment and its impact on missed work and other measures of disability.

“The use of invasive placebos for pain treatment interventions is currently under debate and questions are raised about whether it is justified to expose control group patients to risks of serious harm,” the study authors note. “Because in our study, the treatment’s main objective is pain reduction as experienced by the patients, we decided to use a placebo treatment as control. A placebo intervention, a mixture of saline, lidocaine, and contrast will be injected to establish if there is a pain relief surplus when adding methylene blue into the mixture instead of saline.”