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Test ID LITH Lithium, Serum

Useful For

Monitoring therapy of patients with bipolar disorders, including recurrent episodes of mania and depression

 

Evaluating toxicity

Method Name

Colorimetric

Reporting Name

Lithium, S

Specimen Type

Serum

Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Specimen Volume: 0.5 mL

Collection Instructions: Draw blood 8 to 12 hours after last dose (trough specimen).

Additional Information: Peak serum concentrations do not correlate with symptoms.

Collection Instructions:

1. Serum gel tubes should be centrifuged within 2 hours of collection.

2. Red-top tubes should be centrifuged and aliquoted within 2 hours of collection.

Specimen Minimum Volume

0.25 mL

Specimen Stability Information

Specimen Type Temperature Time
Serum Refrigerated (preferred) 7 days
  Frozen  28 days
  Ambient  72 hours

Clinical Information

Lithium alters the intraneuronal metabolism of catecholamines by an unknown mechanism. It is used to suppress the manic phase of manic-depressive psychosis.

 

Lithium is distributed throughout the total water spaces of the body and is excreted primarily by the kidney.

 

Toxicity from lithium salts leads to ataxia, slurred speech, and confusion. Since the concentration of lithium in the serum varies with the time after the dose, blood for lithium determination should be drawn at a standard time, preferably 8 to 12 hours after the last dose (trough values).

Reference Values

Therapeutic: 0.5-1.2 mmol/L (trough concentration)

Critical value: >1.6 mmol/L

There is no relationship between peak concentration and degree of intoxication.

Cautions

No significant cautionary statements

Day(s) Performed

Monday through Sunday; Continuously

Report Available

Same day/1 day

Performing Laboratory

Mayo Medical Laboratories in Rochester

Test Classification

This test has been cleared or approved by the U.S. Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information

80178

NY State Approved

Yes