Echinacea Versus Placebo Effect in Common Cold (Physician Echinacea Placebo) (PEP)

Placebo: Physician or Pill? A Randomized Trial in a Common Cold Model Funded by NIH NCCAM Under RFA "The Placebo Effect in Clinical Practice"

National Center for Complementary and Integrative Health (NCCIH), National Heart, Lung, and Blood Institute (NHLBI)

The design and interpretation of randomized trials is intimately connected to the use of "placebo". The nature and magnitude of placebo effects, however, is very poorly understood. This study will assess and compare placebo effects and physician interaction effects within a community-acquired common cold model. The goal of this study is to assess two kinds of placebo affects and how physician interaction effects; The effect of receiving blinded placebo, compared to no treatment; and The effect of receiving open-label active Echinacea treatment compared to blinded active treatment.

Echinacea phytochemical profile Each tablet is comprised of the equivalent of 1275 mg of echinacea root, as follows: A) Echinacea purpurea - 675 mg root yields 112.5 mg dried extract, standardized to contain 2.1mg alkamides. B) Echinacea angustifolia - 600 mg root yields 150 mg dried extract, standardized to contain 2.0 mg alkamides. Each batch of tablets is analyzed by Reversed Phase - High Peformance Liquid Chromatography to determine the levels of alkamides and caffeic derivatives present. Caffeic acid derivative levels are typically as follows: caftaric acid = 0.5 to 2.0 mg/tablet; cichoric acid = 3.4 to 8.5 mg/tablet; chlorogenic acid = < 0.5 mg/tablet; dicaffeoyl quinic acids (including cynarin) = 0.7 to 2.0 mg/tablet; echinacoside = 1.0 to 1.7 mg/tablet

Duration and severity of illness, as assessed by the Wisconsin Upper Respiratory Symptom Survey (WURSS-21)

Inclusion criteria: Suspected or known cold At least one of the following cold symptoms: nasal discharge, nasal congestion, sneezing, or sore throat Enrolled in school, for children 12 to 17 years of age Exclusion criteria: Pregnancy; Symptom duration > 36 hrs Concurrent use of antibiotics, antivirals, nasal steroids, decongestants or antihistamines; Anticipated need for symptom-relieving meds during cold Autoimmune/deficiency disease History of allergic rhinitis with current eye itching/sneezing History of asthma w/current cough/SOB Prior study entry Allergy to Echinacea

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Barrett B, Brown R, Rakel D, Mundt M, Bone K, Barlow S, Ewers T. Echinacea for treating the common cold: a randomized trial. Ann Intern Med. 2010 Dec 21;153(12):769-77. doi: 10.7326/0003-4819-153-12-201012210-00003.