A challenging case of syndrome of inappropriate secretion of antidiuretic hormone in an elderly patient secondary to quetiapine.

Hyponatremia secondary to the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) is an uncommon complication of treatment with centrally acting drugs including selective serotonin reuptake inhibitors (SSRIs) and antipsychotic medications. Antipsychotics are commonly used for the treatment of behavioral and psychiatric symptoms in elderly patients with dementia, and the use of those agents is increasing. Here, we report an elderly man who developed hyponatremia after treatment with medications for depression and agitation.