Book Text

Echinacea (Echinacea purpurea)

Echinacea is used in the prophylaxis and treatment of viral, bacterial, and fungal infections, particularly those of upper respiratory origin. However, compelling evidence supporting its use in upper respiratory infections is lacking. ^[18] Patients may also use echinacea as an immunostimulant after chemotherapy and radiation therapy, an adjunct in cancer treatment, and a topical promoter of wound healing.

Echinacea contains alkylamides, alkaloids, caffeic acid esters, polysaccharides, flavonoids, polyacetylenes, and essential oils. Pharmacologic activity cannot be attributed to a single compound, although the lipophilic fraction, which contains the alkylamides (primarily the dodeca-2,4,8,10-tetraenoic acid isobutylamides), polyacetylenes, and essential oil appears to be more active than the hydrophilic fraction.

Echinacea has a number of immunomodulatory effects. In vitro, it activated immune cells, increased cytokine production, and inhibited hyaluronidase. ^[19] In vivo, it activated natural killer cells in humans^[20] and increased production of immunoglobulins G and M in rats.^[21]

Echinacea's immunostimulatory effects may diminish the effectiveness of immunosuppressive medications. Patients awaiting or post-organ transplantation should avoid echinacea. Patients with asthma, atopy, or allergic rhinitis should also avoid this herbal medicine because it is associated with allergic reactions, including one reported case of anaphylaxis.^[22] If taken for more than 8 weeks, echinacea may cause immunosuppression, which may

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**TABLE 15-2** -- Clinically important effects, perioperative concerns, and recommendations for perioperative discontinuation of nine commonly used herbal medicines
Herbs (Common Names)	Important Pharmacologic Effects	Perioperative Concerns	Preoperative Discontinuation
Echinacea	Activation of cell-mediated immunity	Allergic reactions	No data
Purple coneflower root		Decreased effectiveness of immunosuppressants
		Potential for immunosuppression with long-term use
Ephedra (ma huang)	Increased heart rate and blood pressure through direct and indirect sympathomimetic effects	Risk of myocardial ischemia and stroke from tachycardia and hypertension	At least 24 hours before surgery
		Ventricular arrhythmias with halothane
		Long-term use depletes endogenous catecholamines and may cause intraoperative hemodynamic instability
		Life-threatening interaction with MAO inhibitors
Garlic (ajo)	Inhibition of platelet aggregation (may be irreversible)	May increase risk of bleeding, especially when combined with other medications that inhibit platelet aggregation	At least 7 days before surgery
	Increased fibrinolysis
	Equivocal antihypertensive activity
Ginkgo (duck-foot tree, maidenhair tree, silver apricot)	Inhibition of platelet-activating factor	May increase risk of bleeding, especially when combined with other medications that inhibit platelet aggregation	At least 36 hours before surgery
Ginseng (American ginseng, Asian ginseng, Chinese ginseng, Korean ginseng)	Lowers blood glucose	Hypoglycemia	At least 7 days before surgery
	Inhibition of platelet aggregation (may be irreversible)	May increase risk of bleeding
	Increased PT/PTT in animals	May decrease anticoagulant effect of warfarin
	Many other diverse effects
Kava (awa, intoxicating pepper, kawa)	Sedation	May increase sedative effect of anesthetics	At least 24 hours before surgery
	Anxiolysis
		Ability to increase anesthetic requirements with long-term use unstudied
Saw palmetto (dwarf palm, sabal)	Inhibition of 5-α reductase	May increase risk of bleeding	No data
	Inhibition of cyclooxygenase
St. John's wort (amber, goat weed, hardhay, hypericum, Klamath weed)	Inhibition of neurotransmitter reuptake	Induction of cytochrome P450 enzymes, affecting cyclosporin, warfarin, steroids, and protease inhibitors and possibly affecting benzodiazepines, calcium channel blockers, and many other drugs	At least 5 days before surgery
	MAO inhibition is unlikely
		Decreased serum digoxin levels
		Delayed emergence
Valerian (all heal, garden heliotrope, vandal root)	Sedation	May increase sedative effect of anesthetics	No data
		Benzodiazepine-like acute withdrawal
		May increase anesthetic requirements with long-term use
MAO, monoamine oxidase; PT, prothrombin time; PTT, partial thromboplastin time.

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**TABLE 15-3** -- Most commonly used herbal medicines in 2001
1. Echinacea^*
2. Ginkgo biloba^*
3. Garlic^*
4. Ginseng^*
5. Saw palmetto^*
6. Noni (Morinda)
7. St. John's wort^*
8. Soy
9. Ephedra (ma huang)^*
10. Milk thistle
11. Valerian^*
12. Kava^*
13. Grape seed extract
14. Green tea
15. Goldenseal
16. Primrose
17. Black cohosh root
18. Aloe
19. Bilberry
20. Cranberry
Adapted from the Nutritional Business Journal's herbal and botanical U.S. consumer sales.^[9]

*Reviewed in this chapter.

**TABLE 15-4** -- Printed and world wide web sources of herbal medicine information
Source	Comments
Physicians' Desk Reference for Herbal Medicines^[10]
Commission E Monographs^[11]
Textbook of Complementary and Alternative Medicine^[12]
Center for Food Safety and Applied Nutrition, Food and Drug Administration: http://vm.cfsan.fda.gov/∼dms/supplmnt.html	Clinicians should use this site to report adverse events associated with herbal medicines and other dietary supplements. Sections also contain safety, industry, and regulatory information.
National Center for Complementary and Alternative Medicine, National Institutes of Health: http://nccam.nih.gov/	This site contains fact sheets about alternative therapies, consensus reports, and databases.
Agricultural Research Service, United States Department of Agriculture: www.ars-grin.gov/duke	The site contains an extensive phytochemical database with search capabilities.
Quackwatch: www.quackwatch.com	Although this site addresses all aspects of health care, there is a considerable amount of information covering complementary and herbal therapies.
National Council Against Health Fraud: www.ncahf.org	This site focuses on health fraud with a position paper on over-the-counter herbal remedies.
HerbMed: www.herbmed.org	This site contains information on numerous herbal medications, with evidence for activity, warnings, preparations, mixtures and mechanisms of action. There are short summaries of important research publications with Medline links.
ConsumerLab: www.consumerlab.com	This site is maintained by a corporation that conducts independent laboratory investigations of dietary supplements and other health products.

increase the risk of certain postsurgical complications such as poor wound healing and opportunistic infections.^[23] The pharmacokinetics of echinacea have not been studied.