JAMA & ARCHIVES
Arch Fam Med
SEARCH
GO TO ADVANCED SEARCH
HOME  PAST ISSUES  TOPIC COLLECTIONS  CME  PHYSICIAN JOBS  CONTACT US  HELP
Institution: CLOCKSS  | My Account | E-mail Alerts | Access Rights | Sign In
  Vol. 7 No. 6, November 1998 TABLE OF CONTENTS
  Archives
 • Online Features
  Original Contribution
 This Article
 •Full text
 •PDF
 •Send to a friend
 • Save in My Folder
 •Save to citation manager
 •Permissions
 Citing Articles
 •Citation map
 •Citing articles on HighWire
 •Citing articles on Web of Science (69)
 •Contact me when this article is cited
 Related Content
 •Similar articles in this journal
 Topic Collections
 •Complementary and Alternative Medicine
 •Pulmonary Diseases
 •Pulmonary Diseases, Other
 •Alert me on articles by topic

Echinacea Root Extracts for the Prevention of Upper Respiratory Tract Infections

A Double-blind, Placebo-Controlled Randomized Trial

Dieter Melchart, MD; Ellen Walther; Klaus Linde, MD; Roland Brandmaier, MD; Christian Lersch, MD, PhD

Arch Fam Med. 1998;7:541-545.

Objective  To investigate the safety and efficacy of 2 extracts of echinacea for preventing upper respiratory tract infections.

Design  Three-armed, randomized, double-blind, placebo-controlled trial.

Setting  Four military institutions and 1 industrial plant.

Participants  Three hundred two volunteers without acute illness at time of enrollment.

Interventions  Ethanolic extract from Echinacea purpurea roots, Echinacea angustifolia roots, or placebo, given orally for 12 weeks.

Main Outcome Measure  Time until the first upper respiratory tract infection (time to event). Secondary outcome measures were the number of participants with at least 1 infection, global assessment, and adverse effects.

Results  The time until occurrence of the first upper respiratory tract infection was 66 days (95% confidence interval [CI], 61-72 days) in the E angustifolia group, 69 days (95% CI, 64-74 days) in the E purpurea group, and 65 days (95% CI, 59-70 days) in the placebo group (P = .49). In the placebo group, 36.7% had an infection. In the treatment groups, 32.0% in the E angustifolia group (relative risk compared with placebo, 0.87; 95% CI, 0.59-1.30) and 29.3% in the E purpurea group (relative risk compared with placebo, 0.80; 95% CI, 0.53-1.31) had an infection. Participants in the treatment groups believed that they had more benefit from the medication than those in the placebo group (P = .04). Adverse effects were reported by 18 subjects in the E angustifolia group, 10 in the E purpurea group, and 11 in the placebo group.

Conclusion  In this study a prophylactic effect of the investigated echinacea extracts could not be shown. However, based on the results of this and 2 other studies, one could speculate that there might be an effect of echinacea products in the order of magnitude of 10% to 20% relative risk reduction. Future studies with much larger sample sizes would be needed to prove this effect.


From the Center for Complementary Medicine Research (Drs Melchart and Linde and Ms Walther) and Medizinische Klinik (Dr Lersch), Technische Universität; and Biometrisches Zentrum für Therapiestudien (Dr Brandmaier), Munich, Germany.



THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES

Complementary and alternative medicine for prevention and treatment of the common cold
Nahas and Balla
cfp 2011;57:31-36.
ABSTRACT | FULL TEXT  

Echinacea purpurea Therapy for the Treatment of the Common Cold: A Randomized, Double-blind, Placebo-Controlled Clinical Trial
Yale and Liu
Arch Intern Med 2004;164:1237-1241.
ABSTRACT | FULL TEXT  

Echinacea purpurea for Prevention of Experimental Rhinovirus Colds
Sperber et al.
Clinical Infectious Diseases 2004;38:1367-1371.
ABSTRACT | FULL TEXT  

Effectiveness of an Herbal Preparation Containing Echinacea, Propolis, and Vitamin C in Preventing Respiratory Tract Infections in Children: A Randomized, Double-blind, Placebo-Controlled, Multicenter Study
Cohen et al.
Arch Pediatr Adolesc Med 2004;158:217-221.
ABSTRACT | FULL TEXT  

Regulation of Human Immune Gene Expression as Influenced by a Commercial Blended Echinacea Product: Preliminary Studies
Randolph et al.
Exp Biol Med 2003;228:1051-1056.
ABSTRACT | FULL TEXT  

Immune System Effects of Echinacea, Ginseng, and Astragalus: A Review
Block and Mead
Integr Cancer Ther 2003;2:247-267.
ABSTRACT  

Effect of dietary Echinacea purpurea on viremia and performance in porcine reproductive and respiratory syndrome virus-infected nursery pigs
Hermann et al.
J ANIM SCI 2003;81:2139-2144.
ABSTRACT | FULL TEXT  

Treatment of the Common Cold with Unrefined Echinacea: A Randomized, Double-Blind, Placebo-Controlled Trial
Barrett et al.
ANN INTERN MED 2002;137:939-946.
ABSTRACT | FULL TEXT  

The Use of Dietary Supplements in Pediatrics: A Study of Echinacea
Mark et al.
CLIN PEDIATR 2001;40:265-269.
ABSTRACT  

Need for Additional, Specific Information in Studies with Echinacea
Dennehy et al.
Antimicrob. Agents Chemother. 2001;45:369-370.
FULL TEXT  

Pregnancy Outcome Following Gestational Exposure to Echinacea: A Prospective Controlled Study
Gallo et al.
Arch Intern Med 2000;160:3141-3143.
ABSTRACT | FULL TEXT  

Acute disseminated encephalomyelitis after parenteral therapy with herbal extracts: a report of two cases
Schwarz et al.
J. Neurol. Neurosurg. Psychiatry 2000;69:516-518.
ABSTRACT | FULL TEXT  

Immunopharmacological activity of Echinacea preparations following simulated digestion on murine macrophages and human peripheral blood mononuclear cells
Rininger et al.
J. Leukoc. Biol. 2000;68:503-510.
ABSTRACT | FULL TEXT  

Inflammation and Native American medicine: the role of botanicals
Borchers et al.
Am J Clin Nutr 2000;72:339-347.
ABSTRACT | FULL TEXT  

Ineffectiveness of Echinacea for Prevention of Experimental Rhinovirus Colds
Turner et al.
Antimicrob. Agents Chemother. 2000;44:1708-1709.
ABSTRACT | FULL TEXT  

No Support for Echinacea in Preventing URIs
JWatch General 1998;1998:9-9.
FULL TEXT  




HOME | CURRENT ISSUE | PAST ISSUES | TOPIC COLLECTIONS | CME | PHYSICIAN JOBS | HELP
CONDITIONS OF USE | PRIVACY POLICY | CONTACT US | SITE MAP
 
© 1998 American Medical Association. All Rights Reserved.

DCSIMG