Zinc gluconate lozenges for treating the common cold in children - A randomized controlled trial

Context.-The common cold is one of the most frequently occurring illnesses and is responsible for substantial morbidity and economic loss. Biochemical evidence suggests that zinc may be an effective treatment, and zinc gluconate glycine (ZGG) lozenges have been shown to reduce the duration of cold symptoms in adults. Objective.-To determine the efficacy of ZGG treatment of colds in children and adolescents. Design.-A randomized, double-masked, placebo-controlled study. Setting.-Two suburban school districts in Cleveland, Ohio. Patients.-A total of 249 students in grades 1 through 12 were enrolled within the first 24 hours of experiencing at least 2 of 9 symptoms of the common cold. Intervention.-Zinc lozenges, 10 mg, orally dissolved, 5 times a day (in grades 1-6) or 6 times a day (in grades 7-12), Main Outcome Measures.-Time to resolution of cold symptoms based on subjective daily symptom scores for cough, headache, hoarseness, muscle ache, nasal congestion, nasal drainage, scratchy throat, sore throat, and sneezing. Results.-Time to resolution of all cold symptoms did not differ significantly between students receiving zinc (n = 124) and those receiving placebo (n = 125) (median, 9 days; 95% confidence interval [CI], 8-9 days; median, 9 days, 95% CI, 7-10 days, respectively; P=.71). There were no significant differences in the time to resolution of any of the 9 symptoms studied. Compared with controls, more students in the zinc group reported adverse effects (88.6% vs 79.8%; P=.06); bad taste (60.2% vs 37.9%; P=.001); nausea (29.3% vs 16.1%; P=.01); mouth, tongue, or throat discomfort (36.6% vs 24.2%; P=.03); and diarrhea (10.6% vs 4.0%; P=.05). Conclusions.-In this community-based, randomized controlled trial, ZGG lozenges were not effective in treating cold symptoms in children and adolescents. Further studies with virologic testing are needed to clarify what role, if any, zinc may play in treating cold symptoms.