Fluoxetine-induced SIADH: a geriatric occurrence?

After major depression was diagnosed in a 83-year-old woman, fluoxetine was prescribed. Six days later she became delirious and weak, necessitating hospitalization. She was found to have hyponatremia secondary to fluoxetine-induced syndrome of inappropriate antidiuretic hormone secretion (SIADH). Recovery was complete after discontinuation of the medication.