Active therapy with hypertonic NaCl is not indicated in patients with asymptomatic hyponatremia. If the patient is volume depleted, isotonic (154 mmol/l) NaCl is usually the fluid of choice, and if there is a hormone deficiency (cortisol, aldosterone, thyroid hormone) appropriate replacement is indicated. If the patient has received a drug which may interfere with renal handling of sodium or water, it should be discontinued whenever possible. Water restriction is of theoretical benefit in selected disorders, but practical considerations limit its usefulness. With successful fluid restriction (less than 800 ml/day), correction of plasma sodium by more than 1.5 mmol/l daily cannot be expected. Thus water restriction is only appropriate in a patient whose hyponatremia is asymptomatic.
Several medical regimens are available for patients with stable asymptomatic hyponatremia. Demeclocycline in doses above 600 mg/day can produce a state of nephrogenic diabetes insipidus and has been used to treat patients with the syndrome of inappropriate ADH secretion. Other drug regimens of potential benefit in the treatment of chronic hyponatremia (urea, ADH inhibitors) are still experimental.
Was this article helpful?