Symptomatic hyponatremia associated with psychosis, medications, and smoking.

Over a 3-year period, 15 patients with severe hyponatremia were referred to our emergency room from a nearby psychiatric institution. This article reports on 36 episodes of symptomatic hyponatremia in those 15 patients. All but two of the patients were receiving antipsychotic medications; one patient was taking a nonsteroidal anti-inflammatory drug, and one patient was taking an oral hypoglycemic agent. Thirteen patients were chronic schizophrenics, one had a bipolar depressive disorder with psychotic features, and one patient had no psychiatric disorder. Patients presented with seizures, change in mental status, and vegetative symptoms (nausea, vomiting, and diarrhea) associated with hyponatremia and water intoxication. Exacerbation of the patients' underlying illness, psychogenic polydipsia, compulsive smoking, alcoholic cirrhosis, drug abuse, and neuroleptic and other medications are thought to be the major causes of acute hyponatremia in these patients.