Oral urea treatment for polydipsia-hyponatremia syndrome in patients with schizophrenia.

摘要

At least 20% of hospitalized schizophrenic patients demonstrate poly-dipsia and polyuria; more than 25% polydipsic patients may eventually develop hyponatremia, which is called poly-dipsia-hyponatremia syndrome (PHS).1 An acute and severe hyponatremia due to polydipsia can lead to a serious clinical condition called water intoxication, which may cause loss of consciousness, seizures, or even death.1'2 Several pharmacologic approaches have been tested to treat polydipsia in schizophrenic patients; however, none of them has been proven to be effective, thus far.3 Clozapine, a prototype of so-called atypical antipsychotic drugs, may reduce polydipsia in schizophrenic patients.4 Unfortunately, it has serious adverse effects and may not be prescribed for all the patients with PHS; clozapine is not yet approved for clinical use in Japan.