Cis-dichlorodiammineplatinum II-induced syndrome of inappropriate secretion of antidiuretic hormone.

A patient with glioblastoma multiforme developed hyponatremia. This was accompanied by decreased mental awareness and seizures following cis-dichlorodiammine platinum II (DDP) chemotherapy. Treatment with hypertonic saline, furosemide diuresis, and fluid restriction promptly restored the serum sodium and neurologic status to normal. Hyponatremia did not recur despite subsequent tumor progression and increased intracranial pressure. The clinical picture suggested a drug-induced syndrome of inappropriate secretion of antidiuretic hormone. Hyponatremia should be considered when seizures or mental changes occur in patients treated with DDP.