[Therapeutic effect of a mineralocorticoid in patients with hyponatremia of central origin].

Patients with hyponatremia of central origin were treated with a mineralocorticoid, and the therapeutic effect assessed. The subjects of this study were 14 patients (5 with subarachnoid hemorrhage, 2 with hypertensive intracerebral hemorrhage and 7 with head injury) who developed hyponatremia as a complication during their hospital stay for treatment of their intracranial lesions between March 1993 and April 1994. Hyponatremia of central origin was defined as serum Na+ levels below 135 mEq/l for at least two consecutive days with no other discernible etiology. The mineralocorticoid used was fludrocortisone acetate, and as a rule administration was started the day after the onset of hyponatremia. The mean interval until the onset of hyponatremia was 7.5 days, and the mean minimum serum sodium level was 125.7 mEq/l. The dose of fludrocortisone was 0.3 congruent to 0.6 mg/day, the mean period of administration 5.8 days, and route was via a stomach tube in 3 cases and by mouth in 11 cases. The therapeutic effect was good (improvement within 5 days) in 11 cases and fair (improvement in 5 to 8 days) in 3 cases. None of the patients manifested side effects. All of the patients had lower urinary sodium excretion than before administration, with the mean rate of decrease of 66.9%. Mineralocorticoids, which suppress natriuresis, are safe and effective in the treatment of hyponatremia of central origin. It appears that mineralocorticoid therapy may be aggressively tried in severe cases in which NaCl loading is ineffective.