Cold symptoms: Zinc lozenges did not reduce cold symptoms in children and adolescents
Clinical Bottom Line
Zinc gluconate lozenges were not effective for reducing symptoms of the common cold in children and adolescents.
Macknin ML, Piedmonte M, Calendine C, Janosky J, Wald, E. Zinc gluconate lozenges for treating the common cold in children. A randomized controlled trial. JAMA 1998;279:1962-7
In school age children with colds, are zinc lozenges safe and effective for relief of cold symptoms?
Medline (using PubMed) with the search terms zinc AND cold* AND child* AND randomized controlled trial.
- Double-blinded concealed randomised controlled trial with intention-to-treat.
- Students in Grades 1 to 12 (median age 13 y) who had at least 2 of the following symptoms within the previous 24 hours: cough, headache, hoarseness, muscle ache, nasal congestion, nasal drainage, scratchy throat, sore throat, or sneezing.
- Control group (n=125): 3.75 g hard candy lozenges containing sucrose, corn syrup, aminoacetic acid, cherry flavouring oils and placebo (calcium lactate pentahydrate). All students took 3 lozenges each school day; students in grades 1-6 took 2 lozenges each night, and 5 each day on the weekend; students in grades 7 - 12 took 3 lozenges each school night and 6 each day on the weekend. Students were given enough lozenges for 21 days of treatment and instructed to take the lozenges until their cold symptoms completely resolved for 6 hours.
- Experimental group(n=124): Same as for control regimen except that lozenges contained zinc gluconate trichydrate, 10 mg instead of placebo.
|Outcome||Time to Outcome||RRR||95% CI||ARR||95% CI||NNT||95% CI|
|School absences (number of children)||N/A||10%||-38% to 57%||0.020||-0.080 to 0.120||50||NNH = 13 to INF;
NNT = 8 to INF
|At least 1 adverse effect||Resolution of symptoms||-12% (RRI)||-23% to 0%||-0.092 (ARI)||-0.182 to -0.002||-11 (so an NNH of 11)||-441 to -6|
Other outcomes - Time to resolution of cold symptoms was 9 days in both groups
Susan Marks, BA, BEd.
Health Information Research Unit
McMaster University, Hamilton, Ontario, Canada.
Fax: (905) 546-0401
Appraised February 1999.