Syndrome of inappropriate secretion of antidiuretic hormone after infusional vincristine.

A 77-year-old woman with refractory multiple myeloma was treated with a 4-day continuous intravenous infusion of vincristine and doxorubicin and 4 days of oral dexamethasone. Nine days after her second cycle she presented with lethargy and weakness associated with hyponatremia. Evaluation revealed the syndrome of inappropriate secretion of antidiuretic hormone, which was attributed to the vincristine infusion. After normal serum sodium levels returned, further doxorubicin and dexamethasone chemotherapy without vincristine did not produce this complication.