Clinical Concerns About Reduced-Osmolarity Oral Rehydration Solution

Demonstration of the benefits of oral therapy for cholera in 1968¹ soon led to application of the method to all forms of infectious diarrheal diseases.² The original oral rehydration solution (ORS) formulation developed by the World Health Organization (WHO) (Table 1) struck a compromise between the ideal solutions for these diverse disorders to meet the programmatic goal of a single formulation and packaging for global use in cholera and noncholera diarrheas, in both adults and children. Recently, WHO recommended a new oral solution (Table 1) for all acute diarrheas, including cholera. This new formula would replace the original ORS, which saved millions of lives, with a new formulation containing less sodium and glucose.³ This change was ostensibly to reduce gross stool volume and use of unscheduled intravenous therapy by lowering solution osmolarity. However, the reduced-osmolarity formulation is particularly unsuitable for universal use because it contains an amount of sodium insufficient to maintain sodium balance in cholera patients, in whom its use induces negative sodium balance and may lead to hyponatremia,^4,5 polyuria,⁴ and a small but clinically significant risk of neurologic complications. The new reduced-osmolarity formulation stretches the original compromise to the breaking point. It may be time to promote use of different solutions for patients with cholera, beginning in controlled settings such as cholera treatment centers and hospitals.