[Hyponatremic crisis--a serious side effect of diuretics in the elderly]

Treatment with thiazide diuretics is among the most frequent causes of severe hyponatremia. Previous reports indicate that elderly women develop more severe manifestations than men. The risk of developing hyponatremia increases when thiazide diuretics are given simultaneously with NSAIDs.

Three typical case-stories are presented, all cases being admitted to hospital with a tentative diagnosis of cerebrovascular stroke.

It is shown that hyponatremia can give rise to a broad spectrum of symptoms, ranging from unspecific dizziness and headache to alarming neurological symptoms involving lethargy and severe confusion. As far as therapy is concerned, it is important to eliminate the cause of hyponatremia, and to carry out a controlled correction with isotonic or hypertonic saline. Too rapid correction can precipitate a serious complication called osmotic demyelination syndrome.

Differential diagnoses of hyponatremic conditions are discussed. Prescription of drugs that involve risk of hyponatremia should be preceded by a precise evaluation of the condition and the indication for such treatment.