In 2002, the World Health Organization and the United Nations Children's Fund recommended that formulation of oral rehydration solution for diarrhea be changed to 1 with a reduced osmolarity.
It was recommended that safety of the new formulation, particularly development of symptomatic hyponatremia, be monitored.
Dr Nur Alam and colleagues from Bangladesh measured the rates of symptomatic hyponatremia during treatment of diarrhea with reduced osmolarity oral rehydration solution.
The research team conducted a phase 4 trial from 2002 to 2003 at the Dhaka hospital and Matlab hospital of the International Centre for Diarrheal Disease Research Centre in Bangladesh.
All patients admitted with uncomplicated watery diarrhea were treated with the newly recommended oral rehydration solution and monitored.
Patients developing neurological symptoms were transferred to the special care ward for treatment and investigated to identify the cause of the symptoms.
|The estimated incidence rate was 0.10% with symptoms associated with hyponatremia|
|Journal of the American Medical Association|
The team reviewed patient records during the previous year when the old oral rehydration solution formulation was used.
The team's main outcome measure was incidence rate of symptomatic hyponatremia in a 1-year period.
A total of 53,280 patients, including 22,536 children younger than 60 months, were monitored at both hospitals.
The researchers found that 24 patients, none older than 36 months, developed seizures or altered consciousness associated with hyponatremia.
The overall incidence rate was 0.05% at the Dhaka hospital and 0.03% at the Matlab hospital.
During the previous year, the team noted that 47 patients at the Dhaka hospital had symptoms associated with hyponatremia, for an estimated incidence rate of 0.10%.
The researchers observed that the reduction in the rates was statistically significant.
Dr Alam's team concludes, “The risk of symptoms associated with hyponatremia in patients treated with the reduced osmolarity oral rehydration solution is minimal and did not increase with the change in formulation.”