Feverfew (Tanacetum parthenium) and Headache: evidence and sources

Background This review is an update of a previously published review in the Cochrane Database of Systematic Reviews on 'Feverfew for preventing migraine' (2004, Issue 1). Feverfew (Tanacetum parthenium L.) extract is a herbal remedy, which has been used for preventing attacks of migraine. Objectives To systematically review the evidence from double-blind randomised controlled trials (RCTs) assessing the clinical efficacy and safety of feverfew monopreparations versus placebo for preventing migraine. Search methods For this updated version of the review we searched CENTRAL, MEDLINE, EMBASE and AMED to January 2015. We contacted manufacturers of feverfew and checked the bibliographies of identified articles for further trials. Selection criteria We included randomised, placebo-controlled, double-blind trials assessing the efficacy of feverfew monopreparations for preventing migraine in patients of any age. We included trials using clinical outcome measures, while we excluded trials focusing exclusively on physiological parameters. There were no restrictions regarding the language of publication. Data collection and analysis We systematically extracted data on patients, interventions, methods, outcome measures, results and adverse events. We assessed risk of bias using the Cochrane 'Risk of bias' tool and evaluated methodological quality using the Oxford Quality Scale developed by Jadad and colleagues. Two review authors (BW and MHP for this update, MHP and EE for the original version) independently selected studies, assessed methodological quality and extracted data. We resolved disagreements concerning evaluation of individual trials through discussion. Main results We identified one new study for this update, resulting in six trials (561 patients) meeting the inclusion criteria. Five of the six trials reported on the main outcome, migraine frequency. Although five of the trials were generally of good methodological quality, all studies were either of unclear or high risk of bias with regards to sample size. Pooled analysis of the results was not possible due to the lack of common outcome measures and heterogeneity between studies in terms of participants, interventions and designs.The most recent trial added to this version of the review is rigorous and larger (n = 218), using a stable feverfew extract at a dose determined by a previous dose-finding trial. It reports that feverfew reduced migraine frequency by 1.9 attacks from 4.8 to 2.9 and placebo by 1.3 from to 4.8 to 3.5 per month, resulting in a difference in effect between feverfew and placebo of 0.6 attacks per month. For the secondary outcome measures intensity and duration of migraine attacks, incidence and severity of nausea and vomiting, and global assessment no statistically significant differences were reported. Results of previous trials are not convincing: three trials reporting positive effects of feverfew are all of small sample size (17 to 60 participants), while two rigorous trials (n = 50, 147) did not find significant differences between feverfew and placebo. Only mild and transient adverse events, most commonly gastrointestinal complaints and mouth ulcers, were reported in the included trials. Authors' conclusions Since the last version of this review, one larger rigorous study has been included, reporting a difference in effect between feverfew and placebo of 0.6 attacks per month. This adds some positive evidence to the mixed and inconclusive findings of the previous review. However, this constitutes low quality evidence, which needs to be confirmed in larger rigorous trials with stable feverfew extracts and clearly defined migraine populations before firm conclusions can be drawn. It appears from the data reviewed that feverfew is not associated with any major safety concerns.

Objective Feverfew (Tanacetum parthenium L.) is a popular herbal remedy often advocated for the prevention of migraine. The aims of this systematic review are to update the evidence from rigorous clinical trials for or against the efficacy of feverfew for migraine prevention and to provide a safety profile of this herbal remedy. Design Literature searches were performed using the following databases: Medline, Embase, Biosis, CISCOM and the Cochrane Library (all from their inception to December 1999). Only randomized, placebo-controlled, double-blind trials of feverfew mono-preparations for the prevention of migraine in human subjects were included. All articles were read by two independent reviewers. Data were extracted in a pre-defined, standardized fashion. The methodological quality of the trials was evaluated by the Jadad score. For the assessment of safety issues, major reference texts were also consulted. Results Six trials met the inclusion/exclusion criteria. The majority favour feverfew over placebo. Yet important caveats exist. The data also suggest that feverfew is associated with only mild and transient adverse effects and few other safety concerns. Conclusions Feverfew is likely to be effective in the prevention of migraine. There are no major safety problems.

Background Tanacetum parthenium (feverfew) has been used traditionally to treat migraine, and although its mechanism of action is not fully understood, serotonin 5-HT receptor blocking effects have been suggested. T. parthenium and Salix alba (white willow) either alone or in combination (Mig-RL) were recently shown to inhibit binding to 5-HT(2A/2C) receptors; T. parthenium failed to recognise 5-HT(1D) receptors, whereas S. alba or the combination did. It was hypothesised that S. alba in combination with T. parthenium may provide superior migraine prophylactic activity compared with T. parthenium alone. Methods A prospective, open-label study was performed in 12 patients diagnosed with migraine without aura. Twelve weeks' treatment with T. parthenium 300 mg plus S. alba 300 mg (Mig-RL) twice daily was administered to determine the effects of therapy on migraine attack frequency (primary efficacy criterion), intensity and duration (secondary efficacy criteria), and quality of life, together with tolerability for patients. Results Attack frequency was reduced by 57.2% at 6 weeks (p Conclusion The remarkable efficacy of Mig-RL in not only reducing the frequency of migraine attacks but also their pain intensity and duration in this trial warrants further investigation of this therapy in a double-blind, randomised, placebo-controlled investigation involving a larger patient population.