Feverfew For Preventing Migraine

Background The use of herbal medicinal products (HMPs) by the general US population increased by a staggering 480% between 1990 and 1997: according to a national survey (Eisenberg 1998), 1-year population prevalence estimates of HMP use rose from 2.5% in 1990 to 12.1% in 1997. The same survey found that HMPs were most commonly employed for allergies, insomnia, respiratory problems and digestive problems. Estimated 1997 out-of-pocket expenditures for HMPs in the US totaled US$5.1 billion (Eisenberg 1998). Faced with this remarkable interest in HMPs, mainstream healthcare professionals need to familiarise themselves with this subject. The most pressing questions are whether HMPs are effective and safe.

Feverfew (Tanacetum parthenium L.) has traditionally been used for fever, women`s ailments, inflammatory conditions, psoriasis, toothache, insect bites, rheumatism, asthma and stomach-ache. During the last decades, it has also been used for migraine prophylaxis. The sesquiterpene lactone parthenolide has been suggested as the main active component of feverfew. The role of parthenolide in migraine prophylaxis was supported by in vitro studies suggesting inhibition of serotonin release from blood platelets (e.g., Heptinstall 1985). This has, however, been contradicted by other evidence (de Weerdt 1996). At present, the identity of the principle active constituent(s) of feverfew remains unclear.

A systematic review first published in The Cochrane Library, Issue 3, 2000 (Pittler 2000), identified four randomised controlled trials (RCTs) comparing feverfew with placebo for the prevention of migraine, but the data were insufficient to establish the efficacy of feverfew beyond reasonable doubt. The present update sought to identify trials undertaken since the last systematic literature search in 1999 and to address, once again, the questions: (1) does feverfew prevent attacks of migraine, and (2) is it safe to use?