HERBS: Echinacea

Scientific name
Other names
Brand name
Purported uses
Warnings
Contraindications
Adverse reactions
Drug interactions
References

Echinacea

Scientific name

Echinacea purpura, Echinacea angustifolia, Echinacea pallida

Other names

Coneflower, purple coneflower, black Sampson, Sampson root, sonnenhut, igelkopfwurzel

Brand name

Echinagard�, Echinacin�

Purported uses

To treat the common cold: Most clinical trials do not support this use. One clinical trial supports the use of Echinacea for reducing the length of�colds, but not the severity of symptoms.�
As an antiseptic: Laboratory studies suggest that Echinacea has�anti-bacterial qualities. This use has not been tested in humans in clinical trials.
To stimulate the immune system: Laboratory and animal studies suggest that Echinacea extracts stimulate different parts of the immune system.�There is no proof from clinical trials that these effects occur in humans. �
To treat viral infections: Laboratory studies suggest that Echinacea is anti-viral. This use has not been tested in humans other than to treat the common cold.
For faster wound healing: No scientific evidence supports this use.

Warnings

A recent analysis of 59 brand name echinacea products found that 48% did not contain the species of Echinacea on the label and 10% contained no measurable Echinacea. Less than half of the products met the labeled quality standards.

Contraindications

Theoretically, because of potential aggravation of underlying disease state, patients with autoimmune disorders (e.g. systemic lupus erythematosus and rheumatoid arthritis), multiple sclerosis, other progressive collagenous disorders, tuberculosis, HIV, and AIDS should not consume echinacea.

Adverse reactions

Common: Headache, dizziness, nausea, constipation, and mild epigastric pain, rash.
Rare: Dermatitis, anaphylaxis.

Drug interactions

1. Immunosuppressants: Theoretically echinacea may antagonize the effects of immunosuppressants.

2. CYP3A4: Echinacea inhibits CYP3A4 in vitro, indicating that it could theoretically increase serum levels and adverse effects of drugs like alprazolam, calcium-channel blockers, and protease inhibitors.

References

Newall C, et al. Herbal Medicines: A Guide for Health-Care Professionals, 1st ed. London: Pharmaceutical Press; 1996.

1. Schulz V, et al. Rational Phytotherapy: A Physician's Guide to Herbal Medicine, 4th ed. New York: Springer; 2001.

2. Foster S, et al. Tyler's Honest Herbal: A Sensible Guide to the Use of Herbs and Related Remedies. New York: Haworth Herbal Press; 1999.

3. Giles JT, et al. Evaluation of echinacea for treatment of the common cold. Pharmacotherapy 2000;20:690-7.

4. Grimm W, Muller H. A randomized controlled trial of the effect of fluid extract of Echinacea purpurea on the incidence and severity of colds and respiratory infections. Am J Med 1999;106:138-43.

5. Brinker F. Herb Contraindications and Drug Interactions, 3rd ed. Sandy (OR): Eclectic Medical Publications; 2001.

6. Scott GN, Elmer GW. Update on natural product-drug interactions. Am J Health-Syst Pharm 2002;59:339-47.

7. Blumenthal M, et al. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Austin: American Botanical Council; 1998.

8. Schwarz E, et al. Oral administration of freshly expressed juice of Echinacea purpurea herbs fail to stimulate the nonspecific Immune response in healthy young men: results of a double-blind, placebo-controlled crossover study. J Immunother 2002;25: 413-20.

9. Melchart D, et al. Polysaccharides isolated from Echinacea purpurea herba cell cultures to counteract undesired effects of chemotherapy-a pilot study. Phytotherapy Res 2002;16:138-42.

10. Kim LS, et al. Immunological activity of larch arabinogalactan and Echinacea: A preliminary, randomized, double-blind, placebo-controlled trial. Altern Med Rev 2002;7:138-49.

11. Gallo M, Koren G. Can herbal products be used safely during pregnancy? Focus on echinacea. �Can Fam Physician 2001;47:1727-8.

12. Budzinski JW, et al. An in vitro evaluation of human cytochrome p450 3A4 inhibition by selected commercial herbal extracts and tinctures. Phytomedicine 2000;7:273-82.

13. Barrett BP, et al. Treatment of the common cold with unrefined echinacea. A randomized, double-blind, placebo-controlled trial. Ann Intern Med 2002;137:939-46.

14. Gilroy CM, et al. Echinacea and truth in labeling. Arch Intern Med 2003;163:699-704.

15. Melchart D, et al. Echinacea for preventing and treating the common cold. Cochrane Database Syst Rev 2001;4:1-15.

16. Schulten B, et al. Efficacy of Echinacea purpurea in patients with a common cold. A placebo-controlled, randomized, double-blind clinical trial. Arzneimittelforschung 2001;51:563-8.

17. Taylor JA, Weber W, Standish L, Quinn H, Goesling J, McGann M et al. Efficacy and Safety of Echinacea in Treating Upper Respiratory Tract Infections in Children: A Randomized Controlled Trial. JAMA:�JAMA 2003;290:2824-30.