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Test Code LI Lithium, Serum

Specimen Type



Preferred: Red Top tube

Preferred Volume

4 mL

UCMC Collection Instructions

Recommended to draw blood in a plain, red-top tube(s) 8 to 12 hours after last dose (trough specimen). Peak serum concentrations do not correlate with symptoms.

Once per week unless monitoring for removal of toxicity.

Do NOT use mint green lithium heparin tubes for analysis. Specimen will be rejected.



Turnaround Time

3 hours

STAT Availability

Not Available

Test Usage

Monitor therapeutic drug level, support compliance, avoid intoxicating levels

Test Methodology

Ion specific electrode

CPT Code


Test Includes

Quantitative determination of lithium in serum

Reference Range

Adults: 0.5 – 1.0 mEq/L

Critical Results

>2.0 mEq/L

Test Limitations

Lithium toxicity, including severe neurotoxic effects, can occur with normal serum lithium levels. Instances of acute intoxication may be accompanied by high serum lithium levels without clinical evidence of neurotoxic effects. Lithium penetrates neurons slowly. Thiazides can cause significant rise in serum lithium.

Minimum Volume

2 mL

Fee Code