ORS Containing Zinc Does Not Reduce Duration or Stool Volume of Acute Diarrhea in Hospitalized Children

The World Health Organization recommends oral zinc (tablets or syrups) as adjunct therapy with oral rehydration solution (ORS) for acute childhood diarrhea. Mixing zinc with ORS can be an attractive approach for simultaneous provision of these 2 effective interventions. This double-masked randomized controlled trial evaluated the efficacy of ORS containing 40 mg/L elemental zinc per liter (zinc-ORS) in reducing stool weight and duration of diarrhea. Five hundred northern Indian children ages 1 to 35 months with diarrhea <7 days’ duration were randomized to zinc-ORS or ORS. The primary outcomes were total stool output and time to recovery. The median total stool output was 2.12 g · kg-1· h-1(interquartile range [IQR] 0.9–3.76) in the zinc-ORS group compared with 1.78 g · kg-1· h-1(IQR 0.83–3.45) in the ORS group. The time to recovery was also similar in the 2 groups (hazard ratio 1.06 [95% confidence interval 0.88–1.27]). In subjects who received zinc-ORS, the median (IQR) zinc intakes were 27 (16–46) mg on day 1, 15 (6–27) mg on day 2, and negligible thereafter. The World Health Organization–recommended daily dose of zinc for diarrhea was not achieved in most children beyond the first day of treatment. This is the likely explanation for the lack of improvement in outcomes from zinc-ORS when compared with ORS alone. Our findings do not support a change from using zinc syrup or dispersible tablets for treatment of acute diarrhea in children.