Anticonvulsants found to be ineffective for low back pain and can have adverse effects

Anticonvulsant drugs are increasingly being used to treat low back pain, but a new study in CMAJ (Canadian Medical Association Journal) finds they are ineffective and can have adverse effects.

"Clinically, the prescription of anticonvulsants for back and neck pain, including radicular pain in primary care, has increased by 535% in the last 10 years," writes Dr. Oliver Enke, University of Sydney, Sydney Medical School Nepean, Kingswood, Australia, with coauthors, citing data from a recent study on prescribing trends for back pain.

Low back pain affects millions of people and is the number one cause of disability. Clinical practice guidelines usually recommend nonpharmacologic treatments and nonopioid pain relievers rather than stronger analgesics such as anticonvulsants.

The study findings are based on high and moderate-quality evidence from 9 placebo-controlled randomized trials that found a lack of evidence of benefit from anticonvulsants and more adverse events from some of these drugs.

"We have shown, with mostly high- and moderate-quality evidence, that common anticonvulsants are ineffective for chronic low back pain and lumbar radicular pain, and are accompanied by increased risk of adverse events," write the authors.

These findings support recent guidelines from the United States and the United Kingdom that do not recommend the use of anticonvulsants.