Toxic concentration
Early in chronic lithium accumulation, the serum lithium concentration generally reflects the central nervous system (CNS) lithium concentration. There is an approximate correlation between toxic effects and serum lithium concentration—Toxic effects associated with serum lithium concentration provides a guide, but consider the serum lithium concentration in the context of the patient’s clinical presentation and the time since their last dose.
Lithium moves out of the CNS slowly, so neurological recovery may not occur as rapidly as the decrease in serum lithium concentration.
|
Serum lithium concentration |
Toxic effects |
|---|---|
|
0.5 to 1.0 mmol/L (therapeutic) |
no toxicity or minimal toxicity: tremor |
|
1.0 to 2.5 mmol/L |
mild toxicity: tremor, hyperreflexia, nausea, vomiting, diarrhoea |
|
2.5 to 3.5 mmol/L |
moderate toxicity: rigidity, ataxia, drowsiness, confusion |
|
more than 3.5 mmol/L |
severe toxicity: coma, seizures, myoclonus, hypotension, bradycardia, QT-interval prolongation |