Investigators at the Pediatric and Adolescent Ambulatory Community Clinic, Petach Tikva, Israel, sought to prevent respiratory tract infections (RTI) by daily administration of a multi-compound herbal preparation during a single winter. This combination, which contained 4 agents with purported immunomodulatory effects—Echinacea purpurea, E angustifolia, propolis, and vitamin C—was compared with placebo in a randomized, double-blinded clinical trial involving 328 previously healthy children 1 to 5 years of age in the winter of 1999–2000. Each child took either the active combination or placebo twice daily for 12 weeks. The primary outcome measures all related to the number of acute RTIs during the study period. An acute illness was defined as the appearance of 1 or more major signs with at least 1 minor sign after 5 symptom-free days. Major signs included fever greater than 100.4°F (38°C), acute otitis media, tonsillopharyngitis, or pneumonia. Minor signs were hoarseness, stridor, conjunctivitis, cough, or rhinorrhea. Once diagnosed with an acute illness, patients were instructed to increase the frequency of medication administration to 4 times daily.
Children who received the herbal combinations had an average of 0.9 RTIs over the 12-week study period compared with 1.8 RTIs for the placebo group (P<.001). The mean duration of the illnesses was also shorter in the herbal combination group (1.6 days versus 2.9 days; P<.001). The majority of these illnesses were diagnosed as upper respiratory tract infections; the herbal combination group experienced half as many upper RTIs as the placebo group (79 episodes versus 158 episodes; P<.001). The herbal combination group also suffered significantly fewer occurrences of acute otitis media, pneumonia, and tonsillopharyngitis, although no definitions or criteria for diagnosis for any of these illnesses were given. Importantly, the herbal combination group also experienced a significant reduction in days with a fever, antipyretic use, antibiotic use, and daycare or school absence.
Complementary and alternative medicine has become increasingly popular in the United States in recent years, and it is now known that herbal and homeopathic therapies are taken by a large segment of the population including children. 1,2 There is significant concern voiced by the traditional medical community that these compounds have not been subject to the same scrutiny as traditional therapies with respect to both efficacy and safety.3,4
This study contrasts with the recent investigation of the use of E purpurea at the onset of symptoms of an upper respiratory infection5 (see also