PRELIMINARY EVIDENCE OF THE SAFETY OF ECHINACEA IN A RANDOMIZED CONTROLLED TRIAL FOR THE TREATMENT OF COLDS IN CHILDREN.
Authors: Wendy J. Weber, ND; James A. Taylor, MD; Leanna J. Standish, PhD, ND, MS, LAc; Carlo Calabrese, ND, MPH
Purpose: To determine the safety of Echinacea for the treatment of upper respiratory infections (URI's) based on data from the first year of a randomized controlled trial. Methods: After the first year of enrollment, adverse event data was analyzed in a blinded fashion, identified only by group "A" or "B." Children aged 2-11 were recruited from pediatrician offices and advertisements and randomized to receive Echinacea purpurea, in a non-alcoholic syrup, or syrup without active ingredients. Study patients were followed for four months or a maximum of three URI's. At the first symptoms of a URI, parents called the study staff to confirm the start of a URI and were given directions about how to give the study medicine. Surveillance for adverse events was accomplished by reviewing data entered by parents daily into symptom logbooks. In addition, parents were contacted 2-3 times during each URI; the severity of any adverse event reported was assessed using a standardized questionnaire administered over the telephone. Parents could report more than one type of adverse event during each URI. For the analysis, the effect of multiple URI's in the same child was controlled for using Generalize Estimating Equation techiniques. Results: At the time of analysis, there were 146 adverse events reported from the logbooks (70 in group A and 76 in group B) of 356 URI's (186 in group A and 170 in group B). Based on the adverse events collected by phone, no serious adverse events were reported. One adverse event required contact with the family's pediatrician, which was handled over the phone. The types of adverse events reported included stomachache, drowsiness, itching, hyperactivity, diarrhea, rash, vomiting, headache, earache, irritability, and insomnia. Only one of these, hyperactivity, showed a significant difference between group A and B (reported in 10% of URI's in patients in group B and 3.23% of URI's in those in group A, with a two sided P value = 0.03). Conclusion: Due to broad surveillance, a multitude of symptoms related to the URI's were reported in this study. There is no significant or scientifically relevant difference in the total number of adverse events found in the two groups. Based on this preliminary data, Echinacea seems to be safe in the doses used in this study.
