Treatment of recurrent syndrome of inappropriate secretion of antidiuretic hormone with lithium.

The usual treatment for recurrent syndrome of inappropriate secretion of antidiuretic hormone has been fluid restriction. Recently White and Fetner described an adult with SIADH successfully managed with lithium carbonate. Described here is a child with recurrent SIADH who was diagnosed as having an acute hyponatremic episode and who then relapsed twice in a two-month period while chronic fluid restriction was attempted. He has now been maintained on 300 mg/day of lithium carbonate and is asymptomatic with normal serum sodium concentration and urine osmolalities. Lithium appears to be effective in the management of recurrent SIADH and may allow control in a patient who cannot comply with long-term fluid restriction.