Psychogenic polydipsia and hyponatremia – A side effect of psychosis: a review with a case report

Abstract

Primary polydipsia, or psychogenic polydipsia, is a condition that results in considerable morbidity and mortality. In psychiatric patients, psychogenic polydipsia and the syndrome of inappropriate antidiuretic hormone secretion may cause hyponatremia. In the 1970s, it was recognized that antipsychotics such as tiotixene and haloperidol could impair the excretion of a free water load. There are also several case reports of drug-induced hyponatremia in patients using atypical drugs suggesting that these probably can also impair water balance and induce hyponatremia. Case report and review of relevant literature are reported in this article. Psychogenic polydipsia is a common cause of hyponatremia among individuals with chronic mental illness. A case of severe hyponatremia caused by psychogenic polydipsia is described involving a female patient with an adult lifelong history of chronic mental illness diagnosed as schizoaffective disorder. After switching her antipsychotic medication to clozapine water ingestion was normalized as well as sodium levels and her psychotic symptoms improved. Primary polydipsia occurs commonly with schizophrenia and other mental diseases and can cause hyponatremia. PPD may present as an acute psychotic state or as inexplicable emergence of seizures. Appropriate, timely clinical assessment with special attention to thirst, fluid intake, and urine output is essential. Proper treatment may include drug withdrawal and fluid and saline restriction. Once corrected, some pharmacological agents can be tried. The article illustrates the importance of the diagnosis of psychogenic polydipsia given its electrolyte disturbances and life threatening situations.