Zinc for the common cold

Zinc administered as lozenges within 24 hours of onset of common cold symptoms appears to reduce the duration of symptoms, but causes more adverse effects than placebo.

The quality of evidence is downgraded by inconsistency (unexplained variability in results).

Summary

A Cochrane review [withdrawn from The Cochrane Library Issue 4, 2015] included 16 therapeutic trials (1387 participants, adults and children) and two preventive trials (394 participants). Intake of zinc lozenges at a dose of ≥ 75 mg/day was associated with a significant reduction in the duration (days) (MD -1.03, 95% CI -1.72 to -0.34) but not the severity of common cold symptoms (MD -1.06, 95% CI -2.36 to 0.23) (P = 0.11). The proportion of participants who were symptomatic after seven days of treatment was significantly smaller (OR 0.45, 95% CI 0.20 to 1.00) than those in the control. The incidence rate ratio (IRR) of developing a cold (IRR 0.64, 95% CI 0.47 to 0.88), school absence and prescription of antibiotics was lower in the zinc group. Overall adverse events (OR 1.58, 95% CI 1.19 to 2.09), bad taste (OR 2.31, 95% CI 1.71 to 3.11) and nausea (OR 2.15, 95% CI 1.44 to 3.23) were higher in the zinc group.

Clinical comments

The likely benefit of zinc use to shorten the duration of common cold has to be balanced against side effects, notably a bad taste and nausea.

Date of latest search: 2013-01-18

Ədəbiyyat

1. Singh M, Das RR. WITHDRAWN: Zinc for the common cold. Cochrane Database Syst Rev 2015;(4):CD001364 [withdrawn from The Cochrane Library]. .