Antipsychotic-Induced Hyponatremia: Case Report and Literature Review

Abstract

We report a case of hyponatremia in a patient that occurred 3 days after initiation of treatment with aripiprazole. The patient was a 50-year-old man admitted to an inpatient psychiatric unit for exacerbation of schizophrenia. He was started on aripiprazole and developed hyponatremia that resolved when the medication was stopped. We postulate that the hyponatremia was due to an aripiprazole-induced syndrome of inappropriate secretion of antidiuretic hormone. There have been numerous case reports in the literature of hyponatremia in the literature associated with atypical antipsychotics. We caution clinicians to be aware that the potential hyponatremic-inducing effects of atypical antipsychotics can occur rapidly after initiation of the medications.

Syndrome of inappropriate antidiuretic hormone associated with aripiprazole

“…Four other cases of possible aripiprazole-related hyponatremia have been reported in the literature. 22,[27][28][29] In two of these cases, hyponatremia occurred within days of aripiprazole dosage titration to 20 mg per day; in two cases, the patient was reported to be receiving other psychotropic medications that have been associated with SIADH. Our patient was also prescribed bupropion hydrochloride 150 mg twice daily and a high but stable dose of sertraline (300 mg per day).…”

“…Serotonin-mediated effects at the 5-HT 2 and 5-HT 1 receptors on the kidney drive ADH release within the CNS. 21,22 These effects may also lead to a "resetting of the osmostat," or lowering of the sodium threshold by which ADH release is stimulated. 14 As a result, patients with this condition may have lower baseline sodium levels.…”

Hyponatremia and Psychotropic Drugs

“…Hyponatremia is an adverse effect described both in the case of classical and atypical antipsychotics. It is postulated that the etiopathogenesis of hyponatremia in atypical antipsychotics is mediated by the action of serotonin, both by the release of ADH induced by the stimulation of central receptors 5-HT2 and 5-HT1c and by the increase in the effects of ADH at the renal medullary level [15]. In the case of typical antipsychotics, prolonged blockade of dopamine D2 receptors stimulates the release of ADH and increases its peripheral response [16].…”

“…There are currently presentations for oral, parenteral and prolonged release treatment. Literature collects cases of aripiprazole-induced hyponatremia both in patients who developed the symptoms at the start of treatment [15] and in increasing the dose [26], improving in all of them the clinical symptoms with interruption of treatment and water restriction.…”

Hyponatremia in Association With Second-Generation Antipsychotics: A Systematic Review of Case Reports

“…2 However, in most published reports, the drug dosage comparison and the risk association of concomitant interaction are not provided. 2,3,9,[14][15][16][17][18][19][20][21][22][23][24] A 2010 study examining the frequency of reporting hyponatremia with SGA medications in a drug safety database concluded that hyponatremia associated with SGA medications is likely to be underreported because of the concomitant use of other medications known to cause hyponatremia (eg, thiazide diuretics) and potential interaction. 2 The purpose of this systematic review was to examine published cases reporting the use of SGAs and the occurrence of hyponatremia in patients with schizophrenia to inform physicians prescribing SGAs.…”