Lithium toxicity
Overview
Plain-Language Overview
Lithium toxicity occurs when there is too much lithium in the body, a medication commonly used to treat mood disorders like bipolar disorder. It primarily affects the nervous system and the kidneys, leading to symptoms such as tremors, confusion, and muscle weakness. High levels of lithium can disrupt normal brain function and cause serious health problems. The kidneys play a key role in removing lithium, so impaired kidney function can increase the risk of toxicity. Symptoms may develop gradually or suddenly depending on the lithium level and individual factors. Early recognition of signs of toxicity is important to prevent severe complications.
Clinical Definition
Lithium toxicity is a clinical syndrome caused by elevated serum lithium concentrations, usually due to overdose, impaired renal clearance, or drug interactions that reduce lithium excretion. Lithium is a mood stabilizer with a narrow therapeutic index, and toxicity results from its accumulation in the central nervous system and other tissues. The core pathology involves disruption of neuronal signaling and renal tubular function, leading to neurological symptoms such as ataxia, tremor, and altered mental status, as well as renal impairment. Toxicity can be classified as acute, chronic, or acute-on-chronic, each with distinct clinical features. The condition is significant because it can cause life-threatening complications including seizures, coma, and irreversible kidney damage if not promptly recognized and managed.