Acute Hyponatremia Resulting from Duloxetine-induced Syndrome of Inappropriate Antidiuretic Hormone Secretion

Abstract

A 77-year-old woman who had taken a single oral dose of duloxetine subsequently developed a headache and nausea. On the first day, her serum sodium level was 135 mEq/L. She became confused on the third day. Her serum sodium level was 119 mEq/L and her antidiuretic hormone level was 1.9 IU. We diagnosed her with acute hyponatremia from duloxetine-induced syndrome of inappropriate antidiuretic hormone secretion (SIADH). This case suggests that we must not rule out SIADH on the basis of normal serum sodium levels when a patient who has started serotonin-norepinephrine reuptake inhibitor (SNRI) treatment presents with symptoms similar to hyponatremia.

Hyponatremia due to duloxetine use in an elderly woman patient

“…Cases of hyponatremia induced by duloxetine have been described in the literature [8,9]. Our patient's presentation is consistent with literature reports of elderly females who developed hyponatremia within days of being initiated on duloxetine [10][11][12].…”

Acute Severe Hyponatremia Induced by a Duloxetine Overdose in an Elderly Woman

“…Upon admission her sodium was 119 mmol/L, with her baseline being 135 mmol/L one day prior. The hyponatremia resolved after two days [18].…”

“…Our patient reached a nadir of 118 mmol/L on day 4 of hospitalization; however, administration of additional duloxetine doses on days 3 and 4 of hospitalization and the large overdose of duloxetine (450 mg) prior to admission may have prolonged stabilization to seven days. Previous reports have documented hyponatremia within two to five days after initiating duloxetine or after a dose escalation on chronic duloxetine therapy, but have not demonstrated a case this severe and abrupt in the setting of an overdose [7,[9][10][11][12][13][14][15][16][17][18]. Amoako et al described a 76-year-old female treated with duloxetine for fibromyalgia.…”

“…There are multiple reports of patients developing hyponatremia upon initiation or while taking chronic duloxetine [ 7 - 18 ]. We present a case of acute severe hyponatremia due to an overdose of duloxetine, which has not been previously described.…”

Cardiovascular side effects of neuropsychiatric medication: an update

“…Hyponatremia was demonstrated to be relatively a common SE of NPM, while hypokalemia appeared only with SGAs 36,37 . The explication of hyponatremia is the syndrome of inappropriate antidiuretic hormone secretion 38 .…”