Acute lithium intoxication and neuroleptic malignant syndrome.

A 45-year-old man was admitted to our hospital after taking an intentional overdose of 90 sustained-released lithium tablets (450 mg each). The patient was stabilized with three sessions of hemodialysis. On day 7 of his hospital stay, his serum lithium level was 0.5 mEq/L. On day 10, he developed high fever, tachypnea, muscle rigidity, rhabdomyolysis, acute renal insufficiency, mental confusion, and obtundation. His creatine kinase level was 698 IU/L, serum creatinine 3.5 mg/dl. Late-onset neuroleptic malignant syndrome (NMS) was diagnosed. The patient died after developing acute renal failure and acute respiratory distress syndrome. Clinicians should be aware that lithium may cause NMS independent of other neuroleptic agents.