Lithium has been the gold standard in the long-term treatment of bipolar disorder for more than 40 years 1 . Due to a narrow therapeutic index lithium intoxication still is a common but potentially avoidable clinical problem 2 . The possibility of SILENT-syndrome (syndrome of irreversible lithium-effectuated neurotoxicity) illustrates that prevention and optimal treatment of lithium intoxication is vitally important 3 .