WHO Drug Information Vol. 18, No. 2, 2004 - World Health ...

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WHO Drug Information Vol 18, No. 2, 2004
New oral rehydration solution adopted by WHO and UNICEF
For more than 25 years, WHO and UNICEF have recommended a single formulation of glucose
based oral rehydration solution to prevent or treat diarrhoeal dehydration, no matter from what
cause or affected age group. This solution has played a major role in dramatically reducing global
mortality due to diarrhoea. During this time, researchers have sought to develop an ‘improved’ ORS
formulation that was as safe and effective as the original in preventing and treating diarrhoeal
dehydration but also reduced stool output or offered additional clinical benefits. Reducing the
concentrations of glucose and salt in the solution accomplished this goal (see article below).
Because of the improved effectiveness of reduced osmolarity oral rehydration solution, especially
for children with acute, non-cholera diarrhoea, WHO and UNICEF are recommending that countries
manufacture and use the following formulation in place of the previously recommended oral rehydration
solution.
Composition of reduced osmolarity ORS
Reduced osmolarity ORS grams/litre Reduced osmolarity ORS mmol/litre
Sodium chloride 2.6 Sodium 75
Glucose, anhydrous 13.5 Chloride 65
Potassium chloride 1.5 Glucose, anhydrous 75
Trisodium citrate, dihydrate 2.9 Potassium 20
Citrate 10
Total weight 20.5
Total osmolarity 245
A single oral rehydration
solution for global use?
Diarrhoeal diseases remain important causes of
death and morbidity in developing countries, with
an estimated 1.5 billion episodes and 1.5 million
to 2.5 million deaths each year among children
younger than 5 years (1–4). A critical factor in
reducing diarrhoeal deaths has been the widespread
adoption of oral rehydration solution
(ORS) programmes for the treatment and prevention
of diarrhoea-associated dehydration (5, 6). An
article recently appearing in the Journal of the
American Medical Association (7) has proposed
that the composition of oral rehydration solution is
now in need of a revision and proposes the
following argument.
The composition of oral rehydration solution has
proven to be both safe and effective in worldwide
use, based on its efficacy in replacing water and
electrolytes in individuals with cholera infection.
However, concern that the sodium concentration
of 90 mEq/L was too high for the lower salt losses
of viral and other causes of childhood diarrhoea
(8) was invoked to explain its low acceptance
among paediatricians in industrialized countries
who were concerned about the possible occurrence
of hypernatraemia (9). Some authors also
noted that the standard WHO ORS was occasionally
associated with hypernatraemia in children in
developing countries (10).
Based on relevant data, WHO and UNICEF
convened a meeting in 2001 to review all published
studies comparing standard and reducedosmolarity
ORS (11). The conclusions were as
follows: