Initiation of zinc treatment for acute childhood diarrhoea and risk for vomiting or regurgitation: a randomized, double-blind, placebo-controlled trial

The childhood diarrhoea-management guidelines of the World Health Organization/United Nations Children's Fund (WHO/UNICEF) now include zinc treatment, 20 mg per day for 10 days. To determine if a dispersible zinc sulphate tablet formulation is associated with increased risk of vomiting or regurgitation following the initial, first treatment dose, a double-blind, placebo-controlled randomized clinical trial was carried out in the Dhaka hospital of ICDDR,B: Centre for Health and Population Research (n=800) and in an adjacent NGO outpatient clinic (n=800). Children were randomized to one of three groups: no treatment, placebo, or zinc sulphate tablet (20 mg). They were then observed for 60 minutes, and all vomiting or regurgitation episodes were recorded. When compared with placebo, zinc treatment resulted in an attributable risk increase of 14% for vomiting and 5.2% for regurgitation. The median time to vomiting among those receiving zinc was 9.6 minutes and was limited to one episode in 91.2% of the cases. Overall, the proportion of 60-minute post-treatment vomiting attributable to zinc, placebo, and the illness episode was estimated to be 40%, 26%, and 34% respectively. The dispersible zinc sulphate tablet formulation at a dose of 20 mg is associated with increased risks of vomiting and regurgitation. Both are transient side-effects