Table 3:

Alternative and nonpharmacologic interventions for the treatment of the common cold

InterventionFormulation and doseEvidenceRisk of biasOutcomeHarmsComment
Honey71732.5–10 mg, one dose at bedtime3 RCTs (n = 105, 139 and 300 children, respectively); most aged 1–5 yrModerate (multiple trial quality issues, but results highly consistent)Evidence of benefit over placebo and dextromethorphanNo consistent adverse eventsSmall benefit for cough in children (age > 1 yr); no data for adults
Zinc, oral74Different formulations, doses, frequency; zinc gluconate 23-mg lozenge every 2 h most commonMeta-analysis (17 RCTs, n = 2121)Moderate (high or moderate risk of bias in many studies)Pooled analysis of 8 RCTs: reduced duration of cold (mean difference −1.65 d, 95% CI −2.5 to −0.8)Increased adverse events (bad taste and nausea)Probable benefit in adults, but harms present; no benefit in children
Nasal irrigation75Generally, saline drops (children) or irrigationSystematic review and meta-analysis (3 RCTs, n = 618)High (multiple outcomes, most nonsignificant, and quality issues in RCTs)Pooled analysis of 2 RCTs: no difference in nasal symptom score; other results inconsistent13% nasal irritation, 30% dry nose, 40% of infants intolerant of nasal dropsUnclear benefit
Humidified air76Heated water (42°C–47°C ), vapourizedSystematic review and meta-analysis (6 RCTs, n = 394)Moderate (unclear allocation concealment and mixed results)Pooled analysis of 2 RCTs: fewer participants with persistent symptoms (Peto OR 0.31, 95% CI 0.16 to 0.60); very inconsistent results (I2 = 89%)Increased harms, including mask discomfort and increased nasal congestionUnclear benefit
Echinacea50Variable formulations and dosing; E. purpurea most commonSystematic review (14 RCTs, n = 2090)Moderate (some trial quality issues, and inconsistent formulations, cold definitions and results)Inconsistent results (not pooled); for example, 1 of 6 studies showed improved duration and severity of symptomsNo evidence of harmsUnclear benefit
Chinese medicinal herbs77Various formulationsSystematic review (17 RCTs, n = 3212)High (poor trial quality)Data not pooled; 1 of 17 RCTs showed improved severity of symptomsNot reportedUnclear (likely no) benefit
Ginseng78North American ginseng extract in standard dose (26 mg/kg on day 1, 17 mg/kg on day 2, 9 mg/kg on day 3) v. low dose (half the amounts on each day) v. placebo1 RCT (n = 46 children aged 3–12 yr)Low (high-quality trial)No effects reportedNo increase in adverse eventsUnclear benefit
Vitamin C471.5–4 g for 1–5 dMeta-analysis (7 trials, n = 3294 colds)Moderate (reviewers used blinding as a surrogate of allocation concealment)Pooled analysis of 7 RCTs: no effect on durationNo evidence of harmsNo benefit
Zinc, intranasal79,80Zinc nasal spray 33 mmol/L, each nostril 4 times daily (2.1 mg total) in 2 of 3 studiesMeta-analysis (3 studies, n = 453)Moderate (high heterogeneity, possible nonblinding and poor description of randomization)Pooled analysis of 3 RCTs: no significant effect on presence of symptoms at day 3Nasal burning and stinging; unresolved concern of permanent loss of smellDo not use (unclear benefit and possible serious harm may exist)
  • Note: CI = confidence interval, OR = odds ratio, RCT = randomized control trial, RR = rate ratio.