PFPC Daily - April 17, 2005

NOTE: Hyponatremia - Abnormal decrease in blood sodium concentration.

Wakita M, Matsuoka H, Hamada R, Okatsu H, Nakajima T, Osame M
- "Hyponatremia upon resumption of paroxetine therapy" Intern Med
44(3):240-2 (2005)

We present a 79-year-old woman with severe hyponatremia secondary to
resumption of treatment with paroxetine, a selective
serotonin-reuptake inhibitor antidepressant. Confusion and fatigue
followed re-initiation of paroxetine after a 3-month hiatus.
Hyponatremia, serum hypoosmolality, and urine hyperosmolality
strongly suggested the syndrome of inappropriate secretion of
antidiuretic hormone. Hyponatremia was quickly resolved after
discontinuation of paroxetine and initiation of intravenous normal
saline infusion together with oral fluid restriction. This case
underscores the importance of monitoring serum sodium in elderly
patients taking paroxetine, whether this represents a new
prescription or reintroduction of the drug.