Demonstration of the effectiveness of zinc in diarrhoea of children living in Switzerland

Randomized, double-blind, placebo-controlled trial in otherwise healthy children aged 2 months to 5 years with acute diarrhoea at Hôpital de l'Enfance, Lausanne University Hospital in Lausanne, Switzerland. Enrollment occurred from October 2010 to October 2013.

Oral zinc sulphate was given as dispersible tablets for 10 days: 10 mg once daily in children younger than 6 months and 20 mg once daily in children 6 months and older. The regimen was compared with a matched placebo that also contained aspartame.

Zinc improved diarrhoea outcomes in the per-protocol analysis, although the intention-to-treat results were less consistent because of compliance and follow-up issues. Per-protocol median diarrhoea duration was 47.5 hours with zinc versus 76.3 hours with placebo (P=0.03), and diarrhoea frequency between days 2 and 4 was 3 stools versus 9 stools (P=0.02). In the intention-to-treat analysis, persistent diarrhoea at 120 hours was 2/37 (5%) with zinc versus 8/39 (21%) with placebo (P=0.05), while median duration was 65 hours versus 68 hours. The authors concluded that zinc can be effective for diarrhoea management in this developed-country setting, but adherence and formulation or dosing optimization are needed.

Substantial attrition and incomplete analysis sets reduced interpretability, with 42 of 74 randomized zinc participants analyzed and 45 of 74 placebo participants analyzed. Compliance issues affected the intention-to-treat findings, follow-up was short, and adverse events were not reported. The trial was conducted in a single pediatric hospital, limiting generalizability.