[A case of water intoxication presenting as urinary retention in a psychotic patient]

A 43-year-old man, who had been treated for chronic schizophrenia, was admitted to our hospital with the chief complaint of urinary retention. His serum levels of sodium and osmotic value were low and serum creatine phosphokinase (CPK) was elevated to 2,624 mg/dl. He had been consuming about 9 liters of water a day for ten years. A diagnosis of water intoxication was made and treated successfully with water restriction and drip infusion. To our knowledge, this is the 23rd case of water intoxication with serum creatine phosphokinase elevation reported in the Japanese literature and this is the first case with the chief complaint of urinary retention.