Severe Symptomatic Hyponatremia Secondary to Escitalopram-Induced SIADH: A Case Report with Literature Review

Table 2

Diagnostic criteria for the syndrome of inappropriate antidiuretic hormone secretion (SIADH).

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Essential criteria

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1. True plasma hypoosmolality (<275 mOsm/kg H2O)

2. Inappropriate urinary response to hypoosmolality (urine osmolality >100 mOsm/kg H2O)

3. Euvolemia; no edema, ascites, or signs of hypovolemia

4. Elevated urine sodium (>30 mEq/L) during normal sodium and water intake

5. No other causes of euvolemic hyponatremia

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Supplemental criteria

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1. No significant increase in serum sodium after volume expansion, but improvement with fluid restriction.

2. Unable to excrete >80% of a water load (20 cc/kg) in 4 hours and/or failure to achieve urine osmolality <1mOsm/kg H2O

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