Natural Products

Feverfew

Tanacetum parthenium, Chrysanthemum parthenium, Matricaire

Efficacy

• Indications with proven efficacy:
  Migraine (prevention)
• Also used for these other indications, but with no proof of efficacy:
  Arthritis
  Asthma
  Colics
  Earache
  Fever
  Flatulence
  Menstrual irregularities
  Stomachache
  Tinnitus

Security

• Risk of Drug Interactions: Moderate
• Adverse Effects: Not Frequent

What is it?

Feverfew is a perennial plant that can reach 15 to 60 cm high. In Canada, it is found along fields and roads. Because it has green leaves and yellow flowers, it is often mistaken for chamomile. Feverfew has been used in traditional and folk medicine for centuries, especially by the Greeks and European herborists. Even though it has been disregarded for some time, feverfew has made a comeback in recent years as a prophylactic treatment for migraine. Its active principles can be found in the plant's leaves, and the antimigraine effect appears to be related to its parthenolide constituent.

A standardized parthenolide extract called Tanacet is available for the prophylaxis of migraine.

Warning

In 2004, Canada adopted new regulations that control the manufacturing, packaging, labeling and importing of natural health products. The new regulations also include an adverse reaction reporting system. Products that conform to the regulation's criteria are identified with a natural product number (NPN) or homeopathic medicine number (DIN-HM) and can be legally sold in Canada. This number indicates that the product meets specific criteria for safety and purity, not that it is effective for any indication.

Medicinal plants content varies naturally from plant to plant – just as fruits from the same package may vary in taste and texture. There is no standard to measure the active content of each plant. Thus, efficacy of natural products should be expected to vary from brand to brand as well as from bottle to bottle of the same brand.

For more information about the Natural Health Products Regulations, or to check if a product has been assessed, visit the Health Canada website at http://www.hc-sc.gc.ca/dhp-mps/prodnatur/index-eng.php.

Does it work?

Feverfew has been recognized effective in the prophylaxis of migraine. Because some preparations may contain little or no feverfew, standardized products should be preferred.

• Migraine (prevention):
  The usual dose is 2 to 3 fresh leaves or 50 to 250 mg of dried leaves daily, with or without food. Tanacet (standardized to 0.2% parthenolide): 125 mg 1 to 2 times a day after a meal. Improvement may take 4 to 6 weeks of treatment.

There is insufficient reliable information to conclude that feverfew is effective in any other indication.

Is it safe?

• Feverfew is not associated with any severe toxicity. Some mild adverse effects, such as stomachaches, diarrhea, flatulence, nausea or vomiting, have been reported. Mouth ulcerations (aphtes) may occasionally occur when fresh leaves are chewed and, on occasions, feverfew may cause a more extensive inflammation of the mouth and tongue with swelling of the lips and loss of taste.
• This product is contraindicated during pregnancy. Feverfew may stimulate uterine contractions and provoke a spontaneous abortion. Since there is not sufficient reliable information, feverfew should not be used by women who breast-feed.
• People allergic to ragweed, chrysanthenums and daisies may also be allergic to feverfew.
• Feverfew may increase the effects of anticoagulants (Coumadintm) and antiplatelet agents. Anti-inflammatory agents (NSAIDs) may decrease feverfew's activity. Before taking feverfew, check with your pharmacist to make sure that there are no interactions with your regular medication.

Clinical notes

• Up to now, studies evaluating feverfew's effect as a migraine prophylactic have shown significant clinical benefits. In addition, with the exception of mouth ulcerations which may cause some discomfort, feverfew is associated with mild adverse effects, making it a relatively safe product.
• German chamomile (Matricaria chamomilla) and feverfew are two distinct plants with their own specific properties. They are not interchangeable.

References

1. Facts & Comparisons, The Lawrence review of Natural Products, 1999
2. Natural Medicines Comprehensive Database, Therapeutic Research Faculty, 2007
3. Lininger S. et Al. The Natural Pharmacy, Prima Health, 1998
4. Barnes J. et Al. Herbal Medicines, 2nd edition, Pharmaceutical Press, 2002
5. Passeportsanté.net. Grande camomille. http://www.passeportsante.net
6. Taylor J. CE: Phytomedicinals: Uses, precautions, and drug interactions. Drug Topics 2003;1:79
7. Herbal Companion to AHFS DI, American Society of Health-System Pharmacists, 2001
8. Rotblatt M. et Ziment I. Evidence-Based Herbal Medicine, Hanley & Belfus, 2002