Easing Back Pain

Botox, a drug based on the bacteria that causes food poisoning, may be useful in easing low back pain, say researchers.
Researchers from the Walter Reed Army Medical Center in Washington, D.C., studied 31 patients with low back pain. All of the patients had experienced pain for at least six months, with an average of six years, and were taking standard medications, which they continued to take during the study. Patients received either Botox injections or injections of a saline solution. The drug led to significant improvement in about three quarters of those who took it during a study at the Walter Reed

Three weeks after the injections, 73 percent of those who received Botox injections said the amount of pain they experienced had gone down by 50 percent or more. Only 25 percent of those who received the saline said their pain decreased. After eight weeks, 60 percent of those who received Botox said their pain was still decreased by 50 percent or more, compared to 13 percent of those receiving saline.

The patients also filled out a questionnaire, both before the study began and then after eight weeks of treatment, that measured their ability to perform activities of daily life, such as walking, lifting, and traveling. After eight weeks, 67 percent of the patients who received Botox showed improvement in their ability to function, compared to 19 percent of those who received saline. None of the patients reported any side effects from the injections.

Researchers aren’t sure how Botox works to reduce the pain, although they believe the drug reduces the amount and severity of muscle spasms and may also reduce pain by decreasing the input from sensory fibers or by acting on pain receptors.

More studies are needed to determine whether the drug will continue to help patients after repeated injections. That has been the case for patients who receive botulinum toxin injections for other disorders, such as the muscle disorders dystonia and spasticity, so hopefully that will be true for people with low back pain as well.

Source: Neurology, 2001;56:1290-1298