Chlorpropamide-induced hyponatraemia.

A case of hyponatraemia occurring in a 69-year-old diabetic woman taking chlorpropamide is reported. Increasing the dose of chlorpropamide aggravated the hyponatraemia, and the condition corrected itself when the chlorpropamide was withdrawn. It is believed, therefore, that, in the absence of any other cause for the hyponatraemia, chlorpropamide was the cause.