Echinacea

Related Terms

• Alkamides, American coneflower, Asteraceae (family), black sampson, black susan, cichoric acid and polysaccharides, cock-up-hat, combflower, Echinacea angustifolia, Echinacea pallida, Echinacea Plus, Echinacea purpurea, Echinacin®, Echinacin® EC31, Echinaforce®, Echinaforce® Forte, Echinaguard®, Echinilin® (Factors R & D Technologies, Burnaby, BC, Canada), hedgehog, Igelkopf (German), Indian head, Kansas snake root, Kegelblume (German), narrow-leaved purple coneflower, Pascotox®, purple coneflower, red sunflower, rudbeckia, SB-TOX, scurvy root, snakeroot, solhat, sun hat.

Background

• Echinacea species are perennials that belong to the Asteraceae (aster) family and originated in eastern North America. Traditionally used for a range of infections and cancers, the roots and herb (aboveground parts) of Echinacea species have attracted scientific interest for their reported use in enhancing the immune system.
• Natural medicine experts frequently recommend oral extracts of echinacea for the treatment of the common cold and for other conditions requiring immune stimulation. It is occasionally recommended for topical treatment of wounds.
• Traditionally, echinacea roots and herbs were used by indigenous Americans for a wide variety of conditions, ranging from snakebites to cancers. Echinacea does not have U.S. Food and Drug Administration (FDA) Generally Regarded as Safe (GRAS) status.
• Echinacea was adopted by central U.S. settlers in the 1800s. However, after the introduction of antibiotics, echinacea use fell out of favor. Echinacea's historical use as a treatment for infections has found renewed interest due to recent rises in antibiotic resistance and the limitations of available antiviral drugs.

Evidence

*Key to grades: 

A: Strong scientific evidence for this use;
B: Good scientific evidence for this use;
C: Unclear scientific evidence for this use;
D: Fair scientific evidence against this use (it may not work);
F: Strong scientific evidence against this use (it likely does not work).

For full grading rationale, click here.

Safety

The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare professional before starting a new therapy. Consult a healthcare professional immediately if you experience side effects.

Allergies

• Avoid with known allergy or hypersensitivity to Echinacea, its constituents, or any members of the Asteraceae (Compositae) family (including ragweed, chrysanthemum, marigold, and daisy).
• Individuals with asthma may be predisposed to allergic reactions to echinacea.
• Anaphylaxis (a life-threatening allergic reaction), bronchospasm, hives, itching, elevated blood pressure, rash, swelling of both hands, and swelling under the skin have been reported.

Side Effects and Warnings

• Echinacea has been well tolerated in clinical practice and in trials, with few, primarily gastrointestinal, adverse events reported.
• Echinacea may cause abdominal pain, acute kidney failure, allergic rash, atrial fibrillation (irregular heartbeat), dizziness, drowsiness, ear infection (in children), headache, hives, low white cell count, mild nausea, rash, sore throat, tender red nodules under the skin, thrombotic thrombocytopenic purpura (a blood clotting disorder) and vomiting.
• Use cautiously in patients with asthma or those prone to allergic skin reactions, due to a high likelihood of allergic reactions with oral or topical echinacea.
• Use injectable preparations of echinacea (no longer approved for use in Germany) cautiously. Safety has not been established, and in diabetics, injectable administration may worsen blood sugar control.
• Use tinctures cautiously with alcoholic patients or in patients taking disulfiram or metronidazole, as many tinctures contain significant concentrations of alcohol (range: 15-90%). This combination may elicit a disulfiram (strong nausea and vomiting) reaction.
• The German Commission has warned against the use of echinacea in patients with AIDS/HIV, collagen vascular diseases, multiple sclerosis, or tuberculosis, due to theoretical adverse effects on immune function.
• Some natural medicine experts also discourage the use of echinacea by people with conditions affecting the immune system, such as HIV/AIDS, some types of cancer, multiple sclerosis, tuberculosis, and rheumatologic diseases (such as rheumatoid arthritis or lupus).
• Use cautiously in patients with hemochromatosis (iron storage disease), based on a lack of reports on liver function. Numerous reports of hepatitis have been associated with echinacea use.
• Patients consuming large amount of echinacea have experienced elevations in their transaminases (liver function tests).
• Use cautiously in patients who are taking amoxicillin, because there is one poorly described case of rhabdomyolysis and shock, followed by death.
• Use cautiously in patients who are taking anticancer agents.
• Echinacea may interfere with the way the body processes certain drugs, herbs, or supplements using the liver's cytochrome P450 enzyme system. As a result, the levels of these agents may change in the blood, and may cause increased or decreased effects or potentially serious adverse reactions. Patients taking any medications should check the package insert and speak with a qualified healthcare professional, including a pharmacist, about possible interactions.
• Use cautiously in those taking immunostimulants or immunosuppressants, as echinacea may have immunostimulant effects.
• Use cautiously in patients who are taking agents that damage the liver (e.g., anabolic steroids, amiodarone, methotrexate, or ketoconazole), due to a possible risk of hepatitis.
• Use cautiously in patients who are taking kava, due to a possible risk of liver damage. The German Commission Expert panel considers echinacea in recommended doses safe for use (by mouth) during pregnancy and breastfeeding. However, most experts do not recommend injection or infusion of echinacea during pregnancy. Tinctures may not be advised due to their 15-90% alcohol content.
• Avoid using echinacea in patients undergoing anesthesia. Avoid with known allergy or hypersensitivity to Echinacea, its constituents, or any members of the Asteraceae (Compositae) family (including ragweed, chrysanthemum, marigold, and daisy). Anaphylaxis (a life-threatening allergic reaction), bronchospasm, hives, itching, elevated blood pressure, rash, swelling of both hands, swelling under the skin have been reported.

Pregnancy and Breastfeeding

• The German Commission Expert panel considers oral echinacea in recommended doses safe for use in pregnancy and lactation. However, most experts do not recommend injection or infusion of echinacea during pregnancy. Tinctures may not be advised due to their 15-90% alcohol content.

Interactions

Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare professional before starting a new therapy.

Interactions with Drugs

• Echinacea may interfere with the way the body processes certain drugs using the liver's cytochrome P450 enzyme system. As a result, the levels of these drugs may change in the blood, and may cause increased or decreased effects or potentially serious adverse reactions. Patients taking any medication should check the package insert and speak with a qualified healthcare professional, including a pharmacist, about possible interactions.
• Echinacea may interact with agents that damage the liver, amoxicillin, anesthetics, antibiotics, anticancer agents (including cyclophosphamide), antispasmodics, antiviral agents, caffeine, corticosteroids (including prednisone), disulfiram (Antabuse®) or metronidazole (Flagyl®), econazole nitrate (Spectazole®), immunosuppressants (including azathioprine and cyclosporine), influenza vaccine, or water-soluble agents.

Interactions with Herbs and Dietary Supplements

• Echinacea may interfere with the way the body processes certain herbs or supplements using the liver's cytochrome P450 enzyme system. As a result, the levels of other herbs or supplements may become too high or too low in the blood. It may also alter the effects that other herbs or supplements potentially may have on the P450 system.
• Echinacea may interact with anesthetics, antibacterials, anticancer agents, antioxidants, antispasmodics, antivirals, Astragalus, caffeine, Glycyrrhiza, herbs and supplements that may damage the liver, immunostimulants, immunosuppressants, kava, steroids, vitamin B, or water-soluble herbs

Authors

Selected References

Natural Standard developed the above evidence-based information based on a systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to www.naturalstandard.com. Selected references are listed below.

1. Barrett BP, Brown RL, Locken K, et al. Treatment of the common cold with unrefined echinacea. A randomized, double-blind, placebo-controlled trial. Ann Intern Med 2002;137(12):939-946.
2. Barrett B, Brown R, Mundt M, et al. Using benefit harm tradeoffs to estimate sufficiently important difference: the case of the common cold. Med Decis Making 2005;25(1):47-55.
3. Everett LL, Birmingham PK, Williams GD, et al. Herbal and homeopathic medication use in pediatric surgical patients. Paediatr Anaesth 2005;15(6):455-460.
4. Huntley AL, Thompson Coon J, Ernst E. The safety of herbal medicinal products derived from Echinacea species: a systematic review. Drug Saf 2005;28(5):387-400.
5. Koenig K, Roehr CC. Does treatment with Echinacea purpurea effectively shorten the course of upper respiratory tract infections in children? Arch Dis Child 2006;91(6):535-537.
6. Mishima S, Saito K, Maruyama H, et al. Antioxidant and immuno-enhancing effects of Echinacea purpurea. Biol Pharm Bull 2004;27(7):1004-1009.
7. Neri PG, Stagni E, Filippello M, et al. Oral Echinacea purpurea extract in low-grade, steroid-dependent, autoimmune idiopathic uveitis: a pilot study. J Ocul Pharmacol Ther 2006;22(6):431-436.
8. O'Neil J, Hughes S, Lourie A, et al. Effects of echinacea on the frequency of upper respiratory tract symptoms: a randomized, double-blind, placebo-controlled trial. Ann Allergy Asthma Immunol 2008;100(4):384-388.
9. Pillai S, Pillai C, Mitscher LA, et al. Use of quantitative flow cytometry to measure ex vivo immunostimulant activity of echinacea: the case for polysaccharides. J Altern Complement Med 2007;13(6):625-634.
10. Shah SA, Sander S, White CM, et al. Evaluation of echinacea for the prevention and treatment of the common cold: a meta-analysis. Lancet Infect Dis 2007;7(7):473-480.
11. Schapowal A, Berger D, Klein P, et al. Echinacea/sage or chlorhexidine/lidocaine for treating acute sore throats: a randomized double-blind trial. Eur J Med Res 2009;14(9):406-12.
12. Turner RB, Bauer R, Woelkart K, et al. An evaluation of Echinacea angustifolia in experimental rhinovirus infections. N Engl J Med 2005;353(4):341-348.
13. Taylor JA, Weber W, Standish L, et al. Efficacy and safety of echinacea in treating upper respiratory tract infections in children: a randomized controlled trial. JAMA 2003;290(21):2824-2830.
14. Wahl RA, Aldous MB, Worden KA, et al. Echinacea purpurea and osteopathic manipulative treatment in children with recurrent otitis media: a randomized controlled trial. BMC Complement Altern Med 2008;8:56.
15. Yale SH, Glurich I. Analysis of the inhibitory potential of Ginkgo biloba, Echinacea purpurea, and Serenoa repens on the metabolic activity of cytochrome P450 3A4, 2D6, and 2C9. J Altern Complement Med 2005;11(3):433-439.

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