Echinacea purpurea for prevention of experimental rhinovirus colds.
A randomized, double-blind, placebo-controlled clinical trial was conducted to evaluate the ability of Echinacea purpurea to prevent infection with rhinovirus type 39 (RV-39). Forty-eight previously healthy adults received echinacea or placebo, 2.5 mL 3 times per day, for 7 days before and 7 days after intranasal inoculation with RV-39. Symptoms were assessed to evaluate clinical illness. Viral culture and serologic studies were performed to evaluate the presence of rhinovirus infection. A total of 92% of echinacea recipients and 95% of placebo recipients were infected. Colds developed in 58% of echinacea recipients and 82% of placebo recipients (P=.114, by Fisher's exact test). Administration of echinacea before and after exposure to rhinovirus did not decrease the rate of infection; however, because of the small sample size, statistical hypothesis testing had relatively poor power to detect statistically significant differences in the frequency and severity of illness.
Sperber
Steven J
SJ
Department of Internal Medicine, Hackensack University Medical Center, Hackensack, NJ 07601, USA. ssperber@humed.com
Shah
Leena P
LP
Gilbert
Richard D
RD
Ritchey
Thomas W
TW
Monto
Arnold S
AS
D000293:Adolescent; D000328:Adult; D000368:Aged; D003139:Common Cold / Q000188:drug therapy / Q000517:prevention & control*; D004311:Double-Blind Method; D004361:Drug Tolerance; D020900:Echinacea / Q000737:chemistry*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008517:Phytotherapy; D010936:Plant Extracts / Q000009:adverse effects / Q000627:therapeutic use; D010946:Plants, Medicinal; D011897:Random Allocation; D012229:Rhinovirus
D010936:Plant Extracts