Back pain

Several herbal medicines are supported by promising results in terms of alleviating musculoskeletal pain, and many patients who also use such treatments perceive them to be effective. The remedy that has been most thoroughly investigated, specifically for back pain, is devil’s claw ( Harpagophytum procumbens ), which has antiinflammatory and analgesic actions. A systematic review included 4 randomized clinical trials (RCTs) of devil’s claw for back pain. The methodological quality of these studies was mostly good, and collectively their results were encouraging. The review concluded that devil’s claw, at a dose of 100 mg hapagside per day, is an effective symptomatic treatment of back pain ( Table 1 ).

Other herbal medicines that have shown promise in recent clinical trials include willow bark ( Salix alba ) extracts and capsicum creams (see Table 1 ). Willow bark contains salicin (aspirin was derived from willow bark), which has analgesic and antipyretic effects. Capsicum is a powerful skin irritant and acts as a counterirritant relieving pain.

Fibromyalgia

The UK Arthritis Research Campaign (ARC) recently initiated a systematic review of herbal medicines as a treatment of fibromyalgia. Seven clinical trials were located. The effects of oral anthocyanidins and topical capsaicin demonstrated an improvement in sleep disturbance and tenderness, respectively, but not in other end points such as pain. For orally administered soy, the evidence was negative, but only 1 study was found. The ARC review concluded that “there is insufficient evidence” for any herbal medicine as a treatment of fibromyalgia. For the plethora of Chinese herbal medicines, the evidence is, generally speaking, of poor methodological quality and therefore inconclusive. In particular, many studies are underpowered, poorly controlled, and poorly reported.

Fibromyalgia

The UK Arthritis Research Campaign (ARC) recently initiated a systematic review of herbal medicines as a treatment of fibromyalgia. Seven clinical trials were located. The effects of oral anthocyanidins and topical capsaicin demonstrated an improvement in sleep disturbance and tenderness, respectively, but not in other end points such as pain. For orally administered soy, the evidence was negative, but only 1 study was found. The ARC review concluded that “there is insufficient evidence” for any herbal medicine as a treatment of fibromyalgia. For the plethora of Chinese herbal medicines, the evidence is, generally speaking, of poor methodological quality and therefore inconclusive. In particular, many studies are underpowered, poorly controlled, and poorly reported.

Osteoarthritis

A Cochrane review assessed all placebo-controlled RCTs of herbal analgesic treatments of osteoarthritis pain (see Table 1 ). A total of 5 trials using 4 different herbal medicines were identified. The data from the 2 studies that tested avocado-soybean unsaponifiables (ASUs) were pooled, which provided some encouraging evidence. ASUs inhibit interleukin-1 synthesis and have antiinflammatory effects. Another systematic review identified 4 double-blind, placebo-controlled RCTs of ASUs. It concluded that, mainly because of the paucity of the rigorous clinical trials, the clinical evidence is, at present, not fully convincing (see Table 1 ).

A systematic review assessed the effects of devil’s claw for osteoarthritic pain. It included RCTs, quasi-RCTs, and non-RCTs and concluded that there was limited evidence to support the use of an ethanolic extract containing harpagoside, 30 mg/d, in the treatment of knee and hip osteoarthritis. There was a moderate evidence of effectiveness for the use of a devil’s claw powder containing 60 mg harpagoside in the treatment of osteoarthritis of the knee, hip, and spine (see Table 1 ).

A systematic review assessed all RCTs of ginger ( Zingiber officinalis ). Ginger contains a wide range of pharmacologically active ingredients that have been shown to exhibit antiinflammatory activity. Only 1 small RCT ( n = 56) was identified in the review. It reported no difference compared with placebo for Lequesne index and pain caused by osteoarthritis of the knee. However, a more recent, large ( n = 247), double-blind RCT found a reduction in pain. Another double-blind RCT reported superiority of ginger over placebo in terms of pain relief at the end of 6 months. Another RCT reported superiority of ginger extract over placebo but no difference between ginger and ibuprofen in the short term.

The efficacy of Phytodolor (a proprietary preparation which contains Populus tremula , Fraxinus excelsior , and Solidago virgaurea ) in painful arthritic conditions has been assessed in several studies. Several of the constituents are known to have antiinflammatory effects. A systematic review identified 6 double-blind RCTs (see Table 1 ). These trials suggest pain reduction, increase in mobility, and a reduction in the consumption of nonsteroidal antiinflammatory drugs.

A systematic review of rose hip ( Rosa canina ) preparations identified 4 relevant RCTs. The mode of action is not entirely clear, but antiinflammatory effects are likely to play a role. The review concluded that moderate evidence exists for the use of a powder of the seeds and husks of a rose hip subspecies in patients with osteoarthritis of the hip and knee.

SKI 306X is a purified extract from a mixture of 3 herbs ( Clematis mandshurica , Trichosanthes kirilowii , and Prunella vulgaris ). The mechanisms of action are uncertain; most likely they involve antiinflammatory effects. The extract was tested in patients with osteoarthritis of the knee and was found to be superior to placebo when pain was measured with the visual analog scale and Lequesne index. In a trial that compared the herbal mixture with diclofenac, 300 mg/d, both preparations showed similar effects on pain.

Single RCTs, which require independent replications, exist for willow bark ( Salix spp), the herbal mixtures Reumalex and Tipi, a herbomineral formulation, Gitadyl, Eazimov, stinging nettle ( Urtica dioica ), boswellia ( Boswellia serrata ), and the Chinese mixed preparations Duhuo Jisheng Wan, Qianggu, and Garcinia kola. The mechanisms of action involved are diverse but typically involve antiinflammatory effects of the herbal ingredients.