Hyponatremic seizures secondary to oral water intoxication in infancy: association with commercial bottled drinking water.

In recent years, hyponatremic seizures resulting from water intoxication have been reported in the United States with an increasing frequency that some have likened to an epidemic. Infants of parents living in poverty and uninformed of the risks of feeding fluids other than infant formula to their babies are particularly at risk. Young infants with vomiting and diarrhea are especially prone to developing hyponatremia if fed fluids lacking sufficient sodium, but even those who are otherwise well may develop symptomatic hyponatremia as a result of being fed excess solute-free water. Most often tap water, either in the form of supplemental feedings or overly dilute formula, has been given in excessive amounts over relatively short periods of time. Less frequently, water in other forms such as juice, soda, or tea has been implicated. This report includes the cases of two infants treated at our institution for hyponatremic seizures and water intoxication after being fed with the same bottled drinking water product marketed for use in infants. The medical records of all infants </=1 year of age admitted to our institution over 10 years with the diagnosis of hyponatremic seizures were also reviewed.