Lithium Toxicity

Lithium Toxicity

Written by Dr Andrew Lam

Interpretation of Lithium Levels

Therapeutic level – 0.8 – 1.2mmol/L

Mild Toxicity – 1.5 – 2.5mmol/L

Moderate to Severe Toxicity from – 2.5 – 3.5mmol/L 

Severe toxicity – >3.5mmol/L

Symptoms of Toxicity 

Gastrointestinal – nausea, vomiting and diarrhea. (More common in acute toxicity)

Neurological –  ataxia, sluggishness, slurred speech, agitation and tremors. In more severe toxicity, can result in seizures and encephalopathy (More common in chronic toxicity)

Cardiovascular – dysrhythmias and cardiovascular collapse (rarer)

Management of Lithium Toxicity

In acute ingestions – whole bowel contamination with polyethylene glycol:

If immediate release lithium – must be given within 1 hour of ingestion

If sustained release lithium – must be given within 4 hours of ingestion

Judicious fluid resuscitation to allow for intrinsic renal elimination

If levels >5mmol/L or >4mmol/L with renal failure or signs of severe toxicity, elimination with haemodialysis is required. Usually, 1 session of intermittent haemodialysis is sufficient. Repeat lithium levels must be taken 6 hours post-dialysis, and if <1mmol/L, dialysis can be ceased.