Multicenter, randomized, double-blind clinical trial to evaluate the efficacy and safety of a reduced osmolarity oral rehydration salts solution in children with acute watery diarrhea.

OBJECTIVE: To compare the efficacy of a reduced osmolarity oral rehydration salts (ORS) solution (75 mmol/L of sodium [Na], 20 mmol/L of potassium [K], 65 mmol/L of chloride, 10 mmol/L of citrate, and 75 mmol/L of glucose; osmolarity, 245 mosm/L) with that of the standard World Health Organization (WHO) ORS solution.

DESIGN: A multicenter, double-blind, randomized, controlled clinical trial conducted in children with acute diarrhea in 5 developing countries to measure mean stool output in the 24 hours after randomization, proportion of children who required unscheduled intravenous therapy, proportion of children who vomited in the first 24 hours, and diarrhea duration after randomization.

RESULTS: A total of 675 children who ranged in age from 1 to 24 months and who had acute diarrhea and dehydration were enrolled in the trial; 341 were randomized to receive reduced osmolarity ORS solution, and 334 were randomized to receive the WHO ORS solution. The mean (SE) stool output (g/kg) in the first 24 hours (reduced osmolarity ORS solution vs WHO ORS solution = 114 [4] vs 125 [5]) and during the total study period (reduced osmolarity ORS solution vs WHO ORS solution = 320 [18] vs 331 [18]) were comparable. The proportion of children who vomited in the first 24 hours (reduced osmolarity ORS solution vs WHO ORS solution = 58% vs 62%) and the diarrhea duration in the 2 treatment groups, compared by log rank test, were similar. The proportion of children who required unscheduled intravenous therapy was significantly lower in children who received reduced osmolarity ORS solution (10%) as compared with those who received the WHO ORS solution (15%; odds ratio = 0.6, 95% confidence interval = 0.4-1.0). There was no significant difference in the incidence of hyponatremia (serum Na <130 mmol/L) at 24 hours between the 2 treatment groups (11% in reduced osmolarity ORS solution group vs 9% in the WHO ORS solution group; odds ratio = 1.3; 95% confidence interval = 0.8-2.2). The frequency of patients with serum Na <125 mmol/L at 24 hours was 13 of 341 (4%) in children who were treated with reduced osmolarity ORS solution versus 7 of 334 (2%) in children who received the WHO ORS solution.

CONCLUSIONS: Treatment with reduced osmolarity ORS solution was associated with a 33% reduction in the need for unscheduled intravenous therapy and had no apparent effect on stool output and illness duration when compared with treatment with the standard WHO ORS solution. Children with acute diarrhea, therefore, may benefit from a reduced osmolarity ORS solution. The results of trials that examine the efficacy and safety of reduced osmolarity ORS solution in adult patients with cholera have to be taken into consideration before consensus on composition of oral rehydration formulation can be reached.