乌鸦传媒

EDMONTON, Alberta, Aug. 4 -- Ginseng appears safe for treating children with cold and flu symptoms, researchers here found.

An over-the-counter ginseng supplement was well tolerated in children without any serious adverse events or excess in overall adverse events compared with placebo, reported Sunita Vohra, M.D., M.Sc., of the University of Alberta here, and colleagues in the August issue of Pediatrics.

These findings from a randomized phase II safety and tolerability study support use in children, the researchers said.

"In the case of treating the common cold, a self-limiting illness," they wrote, "the minimal clinically important benefit may not be as important as the minimal clinically important harm to families and clinicians, especially with respect to their evaluation in children."

Ginseng and other natural products are commonly used to treat cold and flu symptoms in adults and children alike.

Few, though, have been studied in children, which Dr. Vohra's group said was "especially concerning given that current estimates suggest that 41% to 45% of children in Canada and the United States use natural health products."

To evaluate safety of a commonly used ginseng product among children, the researchers studied 46 children ages three to 12 who developed an upper respiratory tract infection and were randomly assigned to receive placebo or one of two doses of the aqueous ginseng extract (COLD-fX) to be mixed in juice.

The children were pre-recruited with instructions to the parents to call a study nurse within 12 hours of onset of symptoms. If the nurse determined that the symptoms were likely cold or flu, a pharmacy immediately sent out a three-day supply of the supplement or placebo for patients to begin treatment within 48 hours of onset.

The standard adult dose of the supplement was three times daily at 600 mg on day one, 400 mg on day two, and 200 mg on day three. Corresponding doses for children were weight-based and administered at breakfast, after school, and at bedtime.

Standard dose for children was 26 mg/kg per day on day one, 17 mg/kg/day on day two, and 9 mg/kg/day on day three. Children weighing more than 45 kg were given the standard adult dose.

Participants were divided into a standard-dose arm, a low-dose arm (half the standard dose), and a placebo arm.

Adverse event rates overall were similar between treatment groups (standard dose 60%, low dose 80%, placebo 67%, P=0.48).

Only eight adverse events overall were of moderate severity requiring medical attention (six in the placebo group versus two in low-dose group, P=0.02). No severe events occurred.

There was no difference in adverse events classified as possibly related to the intervention by a blinded expert subcommittee (P=0.95).

Although the trial was neither powered nor designed for comparison of efficacy, there was a possible signal that the standard ginseng dose would be most effective in shortening time to symptom resolution.

Patients in the standard ginseng dose arm had the most symptoms at baseline with the highest mean body temperature and highest Canadian Acute Respiratory Infection Flu Scale scores. But they had symptoms resolve as fast as any other group with a time from treatment onset to symptom resolution of 1.5 days compared with 1.9 for low dose, and 1.9 for placebo (P=0.717).

The groups did not differ in use of cold and flu remedies, antibiotics, and asthma medications.

The maker of the ginseng product used in the study, CV Technologies, plans to start a larger randomized efficacy trial in children within the next year, according to a press release.

Further study is also needed to examine the safety of chronic daily use of ginseng in children, "given the growing body of evidence suggesting that ginseng may be an effective upper respiratory tract infection prophylaxis," the researchers said.

The authors pointed out that the study is limited by the concomitant use of natural health products by study participants which could confound interpretation of the treatment effect.