In a
joint report published in April 2012 by the American Academy of Neurology (AAN)
and the American Headache Society (AHS), researchers concluded that a
proprietary extract of butterbur (Petasites
hybridis) root is effective in reducing the frequency of episodic
migraines.1 The finding, published in the journal Neurology, was part of the
organizations’ updated evidence-based treatment guidelines, which specifically examined
the efficacy of what they termed “complementary treatments” and non-steroidal
anti-inflammatory drugs (NSAIDs), such as aspirin and ibuprofen.
“Non-prescriptive
treatments are important for many patients,” said Frederick Freitag, MD, a
co-author of the new guidelines and medical director of The Headache Center of
Baylor Health Care System in Dallas, Texas (email, July 25, 2012). “As with any
treatment for migraine, appropriate discussion with the patient’s clinician
regarding choices and subsequent monitoring for safety and efficacy can be very
beneficial.”
A panel
of headache and methodology experts conducted a literature review of migraine
prevention studies from June 1999 through May 2007 to assess the effectiveness
of non-prescription treatments. Treatments were considered to have established
efficacy if two or more supporting Class 1 human clinical trials existed in the
literature. According to its website, Neurology
defines a Class 1 trial as a “randomized, controlled clinical trial of the
intervention of interest with masked or objective outcome assessment, in a
representative population.”2
Only 2
studies of butterbur extracts for migraine prevention met the criteria for
inclusion, each of which compared placebo treatment to various dosages of the
butterbur root extract supplement Petadolex® (Linpharma Inc.,
Orlando, FL; manufactured in Germany by Weber & Weber of Inning, Germany), which
has been commercially available in Europe for more than 25 years. It has been
available in the United States as a dietary supplement since 1999 (V. Gallichio,
email, August 14, 2012).
Both
studies concluded that certain doses of Petadolex were significantly more
effective than placebo. “Petadolex brand of butterbur root is a reasonable
alternative to prescriptive medication and when properly prescribed and
monitored can be a very effective and safe preventative treatment for
migraine,” said Dr. Freitag.
In their
2001 paper in Alternative Medicine Review
— one of the studies included in the recent migraine prevention literature
review — researchers Werner Grossman
and Hanns Schmidramsl explained
Petadolex’s presumed mechanism of action.3 “Petadolex is an extract
of the rhizome from Petasites hybridus,
and petasine and isopetasine are the main components,” they wrote. “It has been
shown that petasine and isopetasine are strong vasodilatory substances, whereby
this effect on smooth muscle preparations in
vitro is equivalent to papaverine.” (Papaverine is a medication prescribed
for migraines in adults and children, derived from the opium poppy [Papaver somniferum].)
The
etiology of migraines, which are 3 times more common in women, is still
contested. Once thought to be primarily related to cranial vasculature, new
theories — including genetic predisposition, hyperexcitable neurons
(particularly the trigeminal nerve), and inflammation — have emerged in recent
years to explain the causes of these debilitating headaches.4
In
addition to its use for migraine prevention, butterbur root has been used traditionally
for pain management, anxiety, fever, and gastrointestinal conditions. In its
“Herbs at a Glance” factsheet published in March 2012, the National Center for Complementary
and Alternative Medicine (NCCAM) noted the well-known fact that the butterbur
plant contains chemicals known as pyrrolizidine alkaloids (PAs), which have
been shown to cause liver damage.5 NCCAM cautions consumers to use
only butterbur products labeled as PA-free. European regulatory agencies allow
butterbur root and aerial parts preparations to be marketed so long as the
daily dosages stay within a very low prescribed maximum level of PAs. For
example, the German Commission E monograph (under the common name Petasites
Root in the English translation) states that the daily dose of butterbur root
preparations must not exceed 1 mcg of PAs.6
Accordingly,
Petadolex supplements are processed in a manner that reduces PAs to
undetectable levels. As stated on the company’s website, “Petadolex is
manufactured by a patented method for extracting the beneficial liquid of the butterbur
plant without the PAs. This purification process guarantees that Petadolex is
free of detectable PAs.”7
In
addition to butterbur root extracts, experts involved in the recent Neurology report reviewed studies on
antihistamines, Co-Q10, estrogen, hyperbaric oxygen, magnesium, and MIG-99, a
supercritical carbon dioxide-extract of the herb feverfew (Tanacetum parthenium) that is no longer being manufactured (V.
Gallichio, email, August 14, 2012).1 A single Class 1 study and 2
Class 2 studies on MIG-99 and migraine prevention were available in the time
period reviewed by the authors, which was enough evidence to label feverfew
extract as a “Level B” treatment (medications that are “probably effective”).
Although
Petadolex has been shown to be effective in reducing episodic migraines, more
research is needed on other formulations of butterbur, as well as other herbs
that may offer relief to migraine sufferers. Revised guidelines for acute
migraine treatment, separate from preventative treatment, are currently in
development.
—Tyler Smith
References
1. Holland S, Silberstein SD, Freitag
F, Dodick DW, Argoff C, Ashman E. Evidence-based guideline update: NSAIDs and
other complementary treatments for episodic migraine prevention in adults: report
of the Quality Standards Subcommittee of the American Academy of Neurology and
the American Headache Society. Neurology.
2012:78;1346-1353. Available at: www.neurology.org/content/78/17/1346.full.
Accessed August 3, 2012.
2. Levels of evidence. Neurology website. Available at:
www.neurology.org/site/misc/LOEfiller2panels5-31-10.pdf. Accessed August 3, 2012.
3. Grossmann W, Schmidramsl H. An extract
of Petasites hybridus is effective in
the prophylaxis of migraine. Alt Med Rev.
2001;6(3):303-310. Available at: www.thorne.com/media/alternative_
medicine_review/2001/Volume_6/Number_3/Petasites_Migraine.pdf. Accessed August
3, 2012.
4. Evans RW, Evans ER. Expert opinion:
what causes migraine: which physician explanation do patients prefer and understand?
Headache. 2009;49:1536-1540.
Available at:
http://onlinelibrary.wiley.com/doi/10.1111/j.1526-4610.2009.01562.x/abstract.
Accessed August 3, 2012.
5. Butterbur. Herbs at a Glance. The
National Center for Complementary and Alternative Medicine website. Available
at: http://ncaam.nih.gov/health/butterbur. Accessed August 3, 2012.
6. Blumenthal M, Busse WR, Goldberg
A, et al. The Complete German Commission
E Monographs: Therapeutic Guide to Herbal Medicines. Austin, TX: American Botanical Council; Boston, MA: Integrative
Medicine Communications; 1998.
7. FAQs. Petadolex website. Available
at: www.petadolex.com/Faqs.aspx. Accessed August 7, 2012.
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