Chuanxiong chadiao powder, a famous Chinese herbal prescription, for headache: A systematic review and meta-analysis

• A systematic review of trials on the effects of CXCP for headache.
• A total of 3680 participants were included in 37 eligible studies.
• The evidence is supported but limited for CXCP clinical use in treating headache.
• CXCP seem to be safe and well tolerable in patients with headache.

BackgroundHeadache have been recognized as major causes of public ill-health, whereas there currently are the limitations of conventional therapies available. Chuanxiong Chadiao Powder (CXCP) is a well-known classic TCM herbal prescription with respect to treating headache for more than 1000 years. The objective of this study is to systematically assess the clinical efficacy and safety of CXCP for headache.MethodsA systematic literature search in four databases, up to May of 2014, was performed to identify randomized controlled trials (RCTs), which compared CXCP monotherapy or adjunct therapy with western conventional medicine (WCM) or placebo for headache. The primary outcome measures were headache frequency, headache duration, pain intensity scales, globe assessment, patients self report outcomes, and quality of life. The second outcome measures were the total clinical effective rate and adverse events. The methodological quality of RCTs was assessed independently based on the 7 criteria recommended by the Cochrane Back Review Group.ResultsA total of 3680 participants were included in 37 eligible studies. The methodological quality was generally poor and there was only one high quality trial. Meta-analyses of the studies found that significant effects of CXCP for improving headache frequency and headache duration and the total clinical effective rate compared with WCM or placebo control in treating headache (P < 0.01). Adverse event monitoring was reported in 22 studies (59%), while the other 15 studies (41%) did not mentioned.ConclusionsThe evidence from present study is supported but limited for CXCP clinical use in the management of headache because of methodological flaws. Larger sample-sizes and rigorously designed RCTs are required in the future.