Prophylaxis Of Migraine Headache

The first double-blind study investigating feverfew in migraine prophylaxis was published in 1985 and involved 17 patients who had been chewing fresh feverfew leaves on a daily basis (Johnson et al 1985). Therapeutic effect was maintained when capsules containing freeze-dried feverfew powder were continued, whereas those allocated placebo capsules experienced a significant increase in the frequency and severity of headache, nausea, and vomiting during the early months of withdrawal.

Since then, numerous clinical studies have been conducted to determine the role of feverfew in the prevention of migraine headache.

In 2000, Ernst and Pittler published a systematic review of six randomised, placebo-controlled double-blind trials of feverfew as a prophylactic treatment and concluded that the current evidence favours feverfew as an effective preventative treatment against migraine headache, and is generally well tolerated.

Clinical note— Migraine

Migraine is a common episodic familial headache disorder characterised by a combination of headache and neurologic, gastrointestinal, and autonomic symp

toms. It has a 1 -year prevalence of approximately 18% In women, 6% In men, and 4% In children before puberty (Silberstein 2004). Several underlying mechanisms are considered responsible for the onset of migraine.

One of the genes linked to migraine is associated with dysfunction in P-type neuronal calcium channels, which mediate 5-HT and excitatory neurotransmitter release. This dysfunction can impair release of 5-HT and predispose patients to migraine attacks or impair their self-aborting mechanism (Silberstein 2004). Additionally, NO may be involved in the initiation and maintenance of migraine headache (Ferrari 1998). Migraine aura is now thought to be caused by neuronal dysfunction, not ischaemia, and headache begins while cortical blood flow is reduced.

In clinical practice, the three goals of migraine-preventive therapy are to reduce attack frequency, severity, and duration, improve responsiveness to treatment of acute attacks, and improve function and reduce disability. Ultimately, choice of treatment should be based on efficacy, adverse effects and coexistent conditions with a full therapeutic trial taking 2-6 months.

A more recent Cochrane systematic review of five placebo-controlled, randomised, double-blind trials (n = 343) concluded that there was insufficient evidence to determine whether feverfew was superior to placebo in reducing migraine frequency or incidence, severity of nausea or severity of migraines (Pittler & Ernst 2004). A closer look at the studies reveals that results were mixed, methodological quality varied and various dosage regimens, administration forms and extracts were used. One study used three different dosing regimens for a C02 extract, two studies used an alcoholic and C02 extract, three studies used dried feverfew leaves for 8-24 weeks and one study used an alcoholic extract for 8 weeks. Interpretation of test results is made even more difficult when one considers the naturally occurring chemical variations among the preparations.

The authors have offered several explanations for the inconsistent clinical findings and point out that previous negative studies used extracts standardised for parthenolide concentration; however, it is possible that other compounds found in whole-leaf preparations may also be important for pharmacological activity. In vivo studies support this view (Mittra et al 2000). Additionally, the negative results obtained by some studies may be due to under-dosing.

Since then, positive results were obtained for a C02-extract of feverfew in a randomised, double-blind, placebo-controlled, multicentre study of 170 patients (Diener et al 2005). Active treatment with feverfew (MIG-99) at a dose of 6.25 mg,

three times daily, significantly reduced the frequency of migraine headache episodes over a 16-week period.

The Prevention and Treatment of Headaches

The Prevention and Treatment of Headaches

Are Constant Headaches Making Your Life Stressful? Discover Proven Methods For Eliminating Even The Most Powerful Of Headaches, It’s Easier Than You Think… Stop Chronic Migraine Pain and Tension Headaches From Destroying Your Life… Proven steps anyone can take to overcome even the worst chronic head pain…

Get My Free Audio Book


Post a comment