November 10, 1997

A Meta-analysis of Zinc Salts Lozenges and the Common Cold

Author Affiliations

From the Madigan Army Medical Center, Tacoma, Wash. Dr Jackson is now at the Uniformed Services University of the Health Sciences, Bethesda, Md.

Arch Intern Med. 1997;157(20):2373-2376. doi:10.1001/archinte.1997.00440410105012

Background:  In the United States, the common cold has been estimated to cost more than $3.5 billion a year. Despite several randomized clinical trials, the effect of treating colds with zinc salts lozenges remains uncertain because of conflicting results.

Objective:  To conduct a meta-analysis of published randomized clinical trials on the use of zinc salts lozenges in colds using a random effects model.

Results:  Eight clinical trials of treating adults with zinc salts lozenges were identified. After excluding 2 studies that used nasal inoculation of rhinovirus, 6 trials were combined and analyzed. The summary odds ratio for the presence of any cold symptoms at 7 days was 0.50 (95% confidence interval, 0.19-1.29).

Conclusion:  Despite numerous randomized trials, the evidence for effectiveness of zinc salts lozenges in reducing the duration of common colds is still lacking.Arch Intern Med. 1997;157:2373-2376