She had evidence of intravascular volume depletion with a low jugular venous pressure. There were no focal neurologic abnormalities. Her extraocular movements were normal, with no nystagmus. She had a coarse tremor and hyperreflexia with inducible ankle clonus bilaterally. Her mental status was altered, with a Glasgow Coma Scale score of 10 (E4 V2 M4). On examination the patient was afebrile, her blood pressure was 101/54 mm Hg, and heart rate was 110 beats/min and regular. She was not taking any over-the-counter medications or other substances. Her lithium dose had been stable for many years, and there was no history of acute overdose or dosing error. Her prescribed medications were lithium carbonate 900 mg (sustained-release preparation) orally daily, risperidone 3 mg orally daily, benztropine 1 mg orally daily and lorazepam 0.5 mg orally daily as needed.

Her medical history included bipolar I disorder, which had been diagnosed 32 years previously. The syndrome of irreversible lithium-effectuated neurotoxicity (SILENT) is an uncommon complication of lithium toxicity involving persistent and predominantly cerebellar dysfunction.Ī 54-year-old woman presented to the emergency department with a 2-day history of altered mental status, weakness and involuntary movements. Lithium rebound may occur after hemodialysis serum levels should be measured every 4 hours until at least 12 hours after cessation of hemodialysis, ensuring the decline in levels is persistent.

Serum lithium levels are only 1 factor to help guide diagnosis and management, and clinically important chronic toxicity can occur in patients with minimally elevated serum levels.Įarly involvement of the regional poison centre is important in helping to guide management, including the decision to begin hemodialysis. Lithium is a commonly used medication that has a narrow therapeutic index and may lead to important toxicity that can be acute, chronic, or acute on chronic.

Lithium antidote