EFFICACY OF STANDARD GLUCOSE-BASED AND REDUCED-OSMOLARITY MALTODEXTRIN-BASED ORAL REHYDRATION SOLUTIONS - EFFECT OF SUGAR MALABSORPTION

Previously we reported that standard oral rehydration (ORS) solution i s not as effective as a reduced-osmolarity glucose-based ORS for the t reatment of children with acute noncholera diarrhoea: with standard OR S the diarrhoea lasts longer, stool output is greater, serum sodium is higher, and there is more need for supplemental intravenous infusion. We studied a reduced-osmolarity maltodextrin (MD)-based ORS to determ ine whether it had similar benefits, and also the effect of sugar mala bsorption on the efficacy of standard and MD based ORS. A total of 90 boys aged 3-24 months with acute noncholera diarrhoea and moderate deh ydration were randomly assigned to either standard ORS (glucose 20 g/l , osmolarity 311 mmol/l) or MD-ORS (MD 50 g/l, osmolarity 227 mmol/l). There were no differences in treatment results. Some 46% of subjects had a high total stool output (>300 g/kg), which was unrelated to the type of ORS given. High stool output was significantly associated with a longer duration of diarrhoea (33 vs. 15 hours; P < 0.001), a persis tently elevated serum sodium (149 vs 144 mmol/l at 24 h; P < 0.02), th e need for intravenous infusion (11/41 vs 0/48; P < 0.002), and an inc rease in faecal reducing substances (10.8 vs. 3.4 g/l at 24 h; P < 0.0 01). We conclude that some children given standard ORS develop osmotic diarrhoea owing to the combined effect of transient sugar malabsorpti on and slight hypertonicity of the ORS. Earlier studies show that this adverse outcome can largely be avoided when extra water is given in r educed-osmolarity glucose-based ORS. Reduced osmolarity has not benefi t, however, when glucose is replaced by maltodextrin, probably because the sugars released by hydrolysis of MD, when malabsorbed, raise the intraluminal osmolarity to equal or exceed that of standard ORS. Thus, reduced-osmolarity glucose-based ORS is superior to both standard ORS and reduced-osmolarity solutions based on maltodextrin and probably o ther complex carbohydrates. Studies are in progress to define the opti mal formulation of reduced-osmolarity glucose-based ORS.