Occurrence
Feverfew is a perennial found throughout the world.
Uses
Feverfew is used traditionally to treat menstrual irregularities, threatened spontaneous abortion, arthritis, and fever.
Indications
Feverfew (Tanacetum parthenium) is a common
European composite herb with daisylike white flowers
now widely naturalized in the United States.While its
name (a corrupted version of the Latin febrifugia) indicates
a long history in herb lore, feverfew’s current popularity
is due to its use in the prevention and treatment
of migraines. Feverfew has also been used for rheumatoid
arthritis and numerous other conditions with far
less substantiation. The leaves contain sesquiterpene
lactones, including parthenolide, which is thought to be
the most active and important ingredient. Feverfew
preparations are frequently standardized for parthenolide
content, which can vary substantially depending on
time of harvest (levels drop after seeds form) and other
factors. Most studies have used feverfew standardized
to 0.6 to 0.7% parthenolide; the value of leaves containing
less than 0.2% parthenolide is questionable.
General Description
Feverfew, Tanacetum parthenium (L.) Schultz Bip, is an herb that was used in antiquity to reduce fever and pain. The literature is replete with anecdotal evidence of the usefulness of the herb, and recent clinical studies have added more support. Feverfew is a member of the aster/daisy family. The plant tissues have a pungent smell and very bitter taste. The medicinal principle of feverfew is concentrated in hairy trichomes on the chrysanthemum-like leaves.The plant displays clusters of daisylike flowers with yellow centers and radiating white florets. Recent uses of feverfew are for migraine and arthritis, although the indication for arthritis is disputable. The anecdotal evidence that an herb could successfully treat a condition such as migraine headache, naturally begged for some scientific proof. Two prospective clinical studies using dried whole feverfew leaf have been performed to assess the value of the herb in migraine. The two leaf studies on migraine provided good supportive evidence for activity of the herb against migraine.
Mechanism of action
Parthenolide inhibits serotonin release, an action that is
thought to be a likely source of its effectiveness in migraine.
Extracts have also been shown to reduce the
production of prostaglandins (another possible mechanism)
and leukotrienes. Interestingly, melatonin has
been identified in feverfew, a possibly significant observation,
since chronic migraines have been associated
with low melatonin levels.
Clinical Use
At least three studies have demonstrated that feverfew
(dried leaf, not extract) can reduce the frequency and
severity of migraine headaches, although one study failed
to find any significant difference from placebo. Prophylaxis
appears to be more effective than acute treatment.
There is also a consensus that feverfew is probably
less effective than conventional migraine prophylaxis, although
it may have a role as a second-line option.
Although feverfew has also been used for rheumatism, it
has never been verified to be effective in clinical trials.
Side effects
Although feverfew appears generally safe in nonpregnant
adults, the use of fresh leaves has caused mouth irritation
and even ulceration. This is far less likely to occur when the herb is encapsulated. Allergic reactions
(contact dermatitis) have occurred with topical use in
sensitized individuals, and ingestion may also produce
allergic reactions in people with preexisting allergies to
members of the Compositae family. Feverfew has caused
contractions in term pregnancy and has been implicated
in cattle abortions and so should be avoided in pregnancy
and lactation. A feverfew withdrawal syndrome
consisting of joint pain and muscle stiffness may occur
following abrupt discontinuation. Theoretically, because
of its antiprostaglandin effects, feverfew should not be
coadministered with anticoagulants or antiplatelet drugs.
