Herbal Preparation May Prevent Respiratory Tract Infection in Children

March 02, 2004

Yael Waknine

March 2, 2004 -- An herbal preparation containing echinacea, propolis, and vitamin C may be effective in preventive respiratory tract infections in children, according to results of a randomized, double-blind, placebo-controlled multicenter study published in the March issue of the Archives of Pediatric and Adolescent Medicine.

The herbal preparation (Chizukit) is made up of 50 mg/mL of echinacea, 50 mg/mL of propolis, and 10 mg/mL of vitamin C. Echinacea is thought to have cytokine-modulating, macrophage, and natural killer cell activity, according to Herman A. Cohen, MD, and colleagues, from the Pediatric and Adolescent Ambulatory Community Clinic in Petach Tikva, Israel.

Propolis has been shown to have antimicrobial, anticancer, and general anti-inflammatory effects, as well as some antiviral effect on herpes simplex virus type 1 and the influenza virus. Vitamin C is thought to increase proliferative responses of T lymphocytes in vitro, and to induce production of interferon in cell culture. Because concentrations of vitamin C are up to 100 times greater in phagocytes and lymphocytes than in plasma, vitamin C may have a physiologic role in these immune system cells, according to the authors.

The investigators included 430 children aged one to five years in the study. The children were randomized to the herbal preparation (n = 215) or placebo elixir (n = 215) for 12 weeks. Both groups received twice-daily doses of 5.0 mL (age, 1-3 years), or 7.5 mL (age, 4-5 years). Both doses were given four times daily during episodes of acute illness.

Of the initial cohort, 328 children completed the study. Reasons for withdrawal included unpleasant taste, lack of confidence in the treatment, and noncompliance without explanation. Because all drop-outs occurred during the first week of the study, and differences between the groups were insignificant ( P approaching 1.00 for all), an efficacy study was performed instead of an intent-to-treat analysis.

After the drop-out period, 160 children remained in the herbal-preparation group (mean age, 38.3 ± 18.6 months), and 168 children remained in the placebo group (mean age, 38.9 ± 20.6 months). Findings were similar across age groups.

The herbal-preparation group showed a significant decrease in the number of illness episodes compared with the placebo group (138 vs. 308; 55% reduction). The mean number of episodes per child was also significantly decreased (0.9 ± 1.1 vs. 1.8 ± 1.3; 50% reduction; P < .001), as was the mean number of days with fever per child (2.1 ± 2.9 days vs. 5.4 ± 4.4 days; 62% reduction; P < .001).

The total number of illness days was significantly lower in the herbal-preparation group compared with the placebo group (mean, 2.6 ± 4.2 days vs. 6.2 ± 5.0 days; P < .001), as was mean duration of individual episodes (1.6 ± 1.9 days vs. 2.9 ± 1.6 days; P < .001).

Adverse reactions were rare, mild, and transient, and they were similar between the groups ( P = .54). The mild gastrointestinal and palatability symptoms did not require discontinuation of treatment.

"This decrease in upper respiratory tract infections in young children would have significant economic and social ramifications," comments Shilpa Sangvai, MD, from the Children's Hospital of Pittsburgh in Pennsylvania, in an accompanying Journal Club report. "Shortcomings of the study include lack of data comparing demographic characteristics between treatment groups, large attrition resulting in change from intention-to-treat to a per-protocol analysis, and lack of clearly defined outcomes."

"Nevertheless, we find the magnitude of the results compelling," Dr. Sangvai writes.

"Considering that this is the first trial conducted in young children, conclusions must be made with caution," Dr. Cohen and colleagues advise. "Additional studies are needed in larger samples to confirm our findings and to rule out potential adverse effects in general or specific populations at risk, such as allergic children or those receiving cotherapy or having different morbidities, before the preparation can be recommended for routine clinical use."

The study was independently funded. The authors reported no pertinent financial disclosures.

Arch Pediatr Adolesc Med. 2004;158:217-221, 222-224

Reviewed by Gary D. Vogin, MD

Yael Waknine is a freelance writer for Medscape.


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