Acute diarrhoea is a common cause of death and illness in developing countries. Oral rehydration solutions (ORS) have had a massive impact worldwide in reducing the number of deaths related to diarrhoea.
Most ORS is in the form of a sugar–salt solution, but over the years people have tried adding a variety of compounds ('glucose polymers') such as whole rice, wheat, sorghum, and maize. The aim is to slowly release glucose into the gut and improve the absorption of the water and salt in the solution. This review updates and expands on a 1998 Cochrane Review of rice-based ORS, and assesses the available evidence on the use of polymer-based ORS (both rice and non-rice based) in comparison with the glucose-based ORS.
The original ORS was based on glucose and had an osmolarity of ≥ 310 mOsm/L (ORS ≥ 310). Glucose-based ORS with a lower osmolarity was later introduced in attempts to improve efficacy, and is considered better at reducing the amount and duration of diarrhoea.
Thirty-four trials involving 4214 participants met the inclusion criteria: 27 in children; five in adults; and two in both. Most trials compared polymer-based ORS with a sugar–salt ORS with a particular strength (ORS ≥ 310), which is slightly more salty than the currently agreed best formula (≤ 270 mOsm/L). The trials' methodological quality was variable.
Fewer people in the polymer-based ORS group needed a drip to be rehydrated compared with those in the glucose-based ORS group. Adverse events were similar for polymer-based ORS and glucose-based ORS.
The authors conclude that polymer-based ORS show some advantages compared to glucose-based ORS for treating diarrhoea of any cause and in diarrhoea caused by cholera. Limited evidence favoured the polymer-based ORS over ORS ≤ 270. Further trials should compare the efficiency of ORS ≤ 270 with a polymer-based ORS.
Gregorio, G.V.; Dans, L.F.; Martinez, E.G.; Gonzales, M.L.M. Polymer-based oral rehydration solution for treating acute watery diarrhoea. Cochrane Database of Systematic Reviews (2009) (Issue 2) Art. No.: CD006519. [DOI: 10.1002/14651858.CD006519.pub2]