lithium toxicity
Dangerous elevation of lithium blood levels causing neurological, gastrointestinal, and renal symptoms that can be life-threatening.
Full Definition
Lithium toxicity occurs when serum lithium concentrations exceed therapeutic levels, typically above 1.5 mEq/L for maintenance therapy, though toxicity can occur at lower levels in vulnerable patients. Early symptoms include nausea, vomiting, diarrhea, and tremor, progressing to confusion, ataxia, muscle rigidity, and seizures in severe cases. Factors predisposing to toxicity include dehydration, kidney disease, drug interactions (particularly ACE inhibitors, NSAIDs, and thiazide diuretics), fever, and reduced sodium intake. Chronic toxicity may develop insidiously with subtle symptoms, while acute overdose typically presents with more dramatic manifestations. Treatment involves discontinuing lithium, ensuring adequate hydration, and in severe cases, hemodialysis to rapidly reduce serum levels. The narrow therapeutic window of lithium (0.6-1.2 mEq/L for maintenance) necessitates regular monitoring and patient education about factors that can precipitate toxicity.
Usage
Usage note: Distinguish clearly between toxicity (dangerous levels) and common side effects (therapeutic levels); always include specific serum levels when documenting.
In Context
- "The emergency physician suspected lithium toxicity based on the patient's altered mental status and recent gastroenteritis." — Emergency department note
- "Patient education about signs of lithium toxicity and precipitating factors is essential for safe long-term treatment." — Clinical protocol