WINDSOR, Ontario – A Cochrane Back Group review of published trials on herbal treatment for low back pain finds substantial evidence supporting the short-term efficacy of devil's claw, white willow bark, and topical cayenne for treating low back pain. The reviewers, led by naturopathic physician Joel Gagnier, conclude, "These herbal medicines could be considered as treatment options for acute episodes of chronic low back pain."¹

The authors looked at randomized controlled trials of devil's claw extract (Harpago procumbens), white willow bark extract (Salix alba), and cayenne plasters (Capsicum frutescens) in patients with acute, subacute, or chronic low back pain. The review included 10 randomized controlled trials of ~1600 patients. All trials involved comparison of the herbal preparation either to placebo or to active treatment with rofecoxib (Vioxx®), prior to its removal from the market.

The results of these 10 trials suggest that specific herbal medicines may be effective for short-term (4–6 weeks) improvement in pain and functional status for individuals with acute episodes of chronic, nonspecific low back pain," the authors conclude.

Dr. Gagnier told CIAOMed that the reviewers found two high-quality trials with "strong evidence" that devil's claw (50 mg or 100 mg) was better than placebo for short-term improvements in pain and in the need for rescue medications. Strong evidence was defined as "consistent findings among multiple high-quality randomized controlled trials [RCTs]."

"Another high-quality trial showed relative equivalence to 12.5 mg per day of rofecoxib," Dr. Gagnier said.

The reviewers also found two trials with moderate evidence that daily doses of white willow bark standardized to 240 mg salicin were better than placebo for short-term reductions in pain and the need for rescue medications. Moderate evidence was defined as "consistent findings among multiple low-quality RCTs and/or one high-quality RCT."

A third trial found relative equivalence between this dose of white willow bark and 12.5 mg per day of rofecoxib.

The red pepper plasters had been studied only in three low-quality trials. The reviewers "found moderate evidence that Capsicum frutescens produced more favorable results than placebo."

Our biggest question [about all three herbal preparations] is, does this work in the long term? All studies were short-term (less than 12 weeks)," Dr. Gagnier told CIAOMed.

Other clinical concerns are that since herbal preparations are not regulated, they are of uncertain composition, and sometimes interact with other medications in unexpected ways.

Reference

1. Gagnier JJ, van Tulder M, Berman B, Bombardier C. Herbal medicines for low back pain (review). Cochrane Database Syst Rev. 2006;(2)CD004504.