Safety and Efficacy Profile ofEchinacea purpureato Prevent Common Cold Episodes: A Randomized, Double-Blind, Placebo-Controlled Trial

Abstract

Objective. To investigate the safety (risk) and efficacy (benefit) of Echinacea purpurea extract in the prevention of common cold episodes in a large population over a 4-month period. Methods. 755 healthy subjects were allocated to receive either an alcohol extract from freshly harvested E. purpurea (95% herba and 5% root) or placebo. Participants were required to record adverse events and to rate cold-related issues in a diary throughout the investigation period. Nasal secretions were sampled at acute colds and screened for viruses. Results. A total of 293 adverse events occurred with Echinacea and 306 with placebo treatment. Nine and 10% of participants experienced adverse events, which were at least possibly related to the study drug (adverse drug reactions). Thus, the safety of Echinacea was noninferior to placebo. Echinacea reduced the total number of cold episodes, cumulated episode days within the group, and pain-killer medicated episodes. Echinacea inhibited virally confirmed colds and especially prevented enveloped virus infections (P < 0.05). Echinacea showed maximal effects on recurrent infections, and preventive effects increased with therapy compliance and adherence to the protocol. Conclusions. Compliant prophylactic intake of E. purpurea over a 4-month period appeared to provide a positive risk to benefit ratio.

Herbal medicines supplied by community pharmacies in Lagos, Nigeria: pharmacists´ knowledge

“…Over 80% of the respondents either strongly agreed or agreed to herb-herb interaction occurring with herbal medicines, and herb-drug interaction occurring when an herbal medicine was used with conventional medicines. These were in agreement with the various studies that have documented adverse interactions of herbal medicines with other herbal products or conventional medicines 29,3036, only about 40% of the participants in our study always or regularly take the medical or medication history of the potential users.…”

“…They included the locally produced (Yoyo cleanser bitters®, Jobelyn®, Ciklavit®, herbal tea, Yemkem® products, Alomo bitter®, Oroki herbal mixture®, and Ajase poki-poki®) and the imported (ginseng, gingko, Aloe vera, GNLD® products, Forever Living products®, Tianshi® products, Echinacea, St. John’s wort and valerian) herbal medicines. While efficacy and safety data for some of the imported herbal medicines are available in the literature to guide their use28,29,30,31, such data are lacking for the locally produced herbal medicines. The efficacy and safety of the locally produced herbal medicines supplied by the community pharmacies need to be ascertained by the NAFDAC.…”

Echinacea for preventing and treating the common cold

“…Of these, 15 had been included in the previous version of the review (Barrett 2002; Brinkeborn 1999; Bräunig 1992; Dorn 1997; Galea 1996; Goel 2004; Goel 2005; Grimm 1999; Hoheisel 1997; Kim 2002a; Lindenmuth 2000; Melchart 1998; Schulten 2001; Taylor 2003; Yale 2004), two of the now included studies on induced colds had initially been excluded in the previous version of the review (Sperber 2004; Turner 2000) and seven studies have been newly included (Barrett 2010; Hall 2007; Jawad 2012; O’Neill 2008; Tiralongo 2012; Turner 2005; Zhang 2003). One study (Taylor 2003) was in children, the other 23 in adults.…”

“…In four of these trials 431 healthy volunteers (Hall 2007) or persons being challenged by inoculation with rhinovirus (Sperber 2004; Turner 2000; Turner 2005) were treated over a shorter period (two to four weeks). Six trials including 1391 participants (Grimm 1999; Jawad 2012; Melchart 1998; O’Neill 2008; Tiralongo 2012; Zhang 2003) treated healthy volunteers over a longer period (6 to 16 weeks) for preventative purposes.…”

“…Preparations based on E. purpurea root alone were used in two trials, with three experimental groups (Bräunig 1992; Zhang 2003). An identical product based on a mixture of E. purpurea root (5%) and herb (95%) was used in two trials with three experimental groups (Brinkeborn 1999; Jawad 2012). One of these trials (Brinkeborn 1999) tested two different concentrations of the same product.…”