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Lithium Toxicity — SCE Neurology MCQ

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ModerateNeuropsychiatryLithium ToxicitySCE Neurology

A 55-year-old woman with bipolar disorder on long-term lithium therapy presents with coarse tremor, cerebellar ataxia, hyperreflexia, and drowsiness. Her lithium level is 3.2 mmol/L. What is the most important immediate management step?

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Correct answer: D — Stop lithium and commence IV fluid resuscitation; consider haemodialysis

Lithium levels >3.0 mmol/L indicate severe lithium toxicity, which is a medical emergency. Management includes stopping lithium, aggressive IV fluid resuscitation with normal saline, and haemodialysis for levels >3.5 mmol/L or severe neurological toxicity at any level. Lithium has a narrow therapeutic index (0.6–1.0 mmol/L for maintenance). A: This would worsen toxicity. C: Activated charcoal does not effectively bind lithium. D: Phenytoin has no role. E: Propranolol is for essential tremor, not lithium toxicity.

Reference: BNF; NICE CG185 Bipolar Disorder (2014)