A systematic review of the ability of urine concentration to distinguish antipsychotic- from psychosis-induced hyponatremia

Abstract

Life-threatening hyponatremia in psychotic patients is common and typically is attributable to either antipsychotic medication or to acute psychosis in those with the polydipsia-hyponatremia syndrome. The preferred treatment for one situation may worsen the hyponatremia if caused by the other situation. Hence it is critical to distinguish between these two possibilities. Case reports and series were identified through electronic databases. 54 cases of hyponatremia without recognized causes in psychotic patients were divided into those with dilute (< plasma osmolality) or concentrated (> plasma osmolality) urine. The distribution of urine concentration and measures likely to be associated with psychotic illness and its treatment were compared in both groups. Naranjo’s scale was utilized to determine the probability hyponatremia was drug-induced. Urine osmolality fit a bimodal distribution (intersection 219 mOsm/Kg) better than a unimodal distribution. ‘Probable’ drug-induced cases occurred 6.8 (95%CI=1.6–28.9) times more often in those with concentrated urine. Acute psychotic exacerbations occurred 4.5 (95%CI=0.4–54.1) times more often in those with dilute urine. These findings, as well as several other trends in the data, indicate that measures of urine concentration can help distinguish between antipsychotic-induced and psychosis-induced hyponatremia.

Disorders of Plasma Sodium — Causes, Consequences, and Correction

“…28 Hypernatremia develops if water is unavailable, if the urge to drink is impaired (hypodipsia), or if patients are too young, old, or sick to seek water themselves. 35 Maximal dilution of urine prevents hyponatremia unless water intake is extraordinarily large (>1 liter per hour) (e.g., in patients with schizophrenia who drink water compulsively) 36 or the rate of urinary solute excretion is extremely low (e.g., in beer drinkers who eat very little). 20,37 Except in these scenarios, hypotonic hyponatremia is associated with an impaired ability of the body to dilute urine because of diminished sodium transport in renal-diluting sites (most commonly because of the use of diuretics), 38 the presence of vasopressin, 39,40 or, rarely, an inherited activating mutation of the vasopressin receptor.…”

Brain circuit dysfunction in a distinct subset of chronic psychotic patients

“…During the latter half of the 20 th century, these unexplained impairments in water excretion and intake were recognized as common causes of morbidity and a frequent cause of death in schizophrenia patients (De Leon et al, 1994; Hawken et al, 2009; Vieweg et al, 1985). More recent studies suggest these patients can be relatively easily distinguished from patients whose hyponatremia is attributable to recognized causes (Atsariyasing and Goldman, 2014; Ittaskul and Goldman, 2014). Primary polydipsia and evidence of impaired water excretion are found in 10–25% and 2–5% of chronic psychotic patients respectively, depending on the criteria used to define water imbalance.…”

Hiponatremia in the practice of a psychiatrist. Part 1: SIADH syndrome and drug-induced hyponatremia.

“…antipsychoticand psychosis-induced hyponatremia, as described by Atsariyasing and Goldman [55]. The authors searched the MEDLINE database from 1960 to September 2012, taking into account the works previously analyzed by Meulendijks et al, using keywords: hyponatremia, SIADH, antipsychotics, and English.…”

“…Analizując problem hiponatremii u pacjentów leczonych z rozpoznaniem zaburzeń psychotycznych należy zróżnicować dwie kwestie: hiponatremię indukowaną leczeniem przeciwpsychotycznym oraz hiponatremię indukowaną samą psychozą, do czego odnoszą się Atsariyasing i Goldman [55]. Autorzy przeszukali bazę ME-DLINE od 1960 roku do września 2012 roku, uwzględnia-jąc prace analizowane wcześniej przez Meulendijks i wsp., używając słów-kluczy: hiponatremia, SIADH, leki przeciwpsychotyczne, język angielski.…”