Lab Test

Lithium Level, Serum

Antrim #15960, EPIC: LAB5400, SOFT: LITHI

Test Codes

Antrim #15960, EPIC: LAB5400, SOFT: LITHI

Specimen Collection Criteria

Collect (preferred specimen): One Gold-top SST tube.
Also acceptable: One plain Red-top tube.

Time of Collection: Trough, just prior to the next dose.
Record the exact time of specimen collection on the tube or in the computer system.

Physician Office/Draw Specimen Preparation

Let specimens clot 30-60 minutes and refrigerate (2-8°C or 36-46°F) the collection tube within two hours of collection. (Minimum: 1.0 mL blood)

Preparation for Courier Transport

Transport: Collection tube, refrigerated (2-8°C or 36-46°F). (Minimum: 1.0 mL blood)

Rejection Criteria

  • Severely lipemic or hemolyzed specimens.

In-Lab Processing

Let specimens clot 30-60 minutes. Centrifuge specimen to separate serum from cells. Deliver an aliqout of serum or the collection tube immediately to the appropriate testing station.


Specimen Stability for Testing:

Centrifuged Collection Tubes
Room Temperature (20-26°C or 68-78.8°F): 24 hours
Refrigerated (2-8°C or 36-46°F): 7 days
Frozen (-20°C/-4°F or below): Unacceptable

Serum Specimens (Pour-Overs)
Room Temperature (20-26°C or 68-78.8°F): 24 hours
Refrigerated (2-8°C or 36-46°F): 7 days
Frozen (-20°C/-4°F or below): 3 months

Specimen Storage in Department Prior to Disposal:

Refrigerated (2-8°C or 36-46°F): 7 days


Farmington Hills Chemistry Laboratory
Royal Oak Toxicology Laboratory


Sunday – Saturday, 24 hours a day.
STAT results available within 1 hour of receipt in the Laboratory.
Routine results available within 24 hours.

Reference Range

Therapeutic Range: 0.6-1.2 mmol/L
Critical Range: Greater than 1.5 mmol/L

Test Methodology



Lithium is used for the treatment of manic-depressive illness. Values of greater than 1.5 mmol/L indicates an increased risk of intoxication. Severe intoxication, characterized by muscle rigidity, hyperactive deep tendon reflexes, and epileptic seizures, is usually associated with lithium concentrations greater than 2.5 mmol/L. Lithium is eliminated renally. Lithium can cause renal toxicity, thereby inhibiting its own elimination.

Clinical Utility

This assay is used to monitor the therapeutic drug level and evaluate the toxicity of lithium.

CPT Codes



Last Updated


Microtainer® and Vacutainer® are registered trademarks of Becton, Dickinson and Company.
UroVysion® is a registered trademark of Abbott Laboratories. ThinPrep® is a registered trademark of Hologic, Incorporated.


This directory currently reflects information only for specimens collected and/or processed at the
Farmington Hills, Grosse Pointe, Royal Oak, and Troy campuses.