Lithium CPT: 80178
Expected Turnaround Time
Within 1 day
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Specimen Requirements
Specimen
Serum
Volume
1 mL
Minimum Volume
0.5 mL
Container
Red top
Collection
1. Draw blood 8 to 12 hours after last dose (trough specimen).
2. Serum gel tubes should be centrifuged within 2 hours of collection.
3. Red-top tubes should be centrifuged and aliquoted within 2 hours of collection.
Additional Information: Peak serum concentrations do not correlate with symptoms.
Storage Instructions
Maintain specimen at room temperature.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 8 hours |
| Refrigerated | 24 hours |
| Frozen | 6 months |
| Freeze/thaw/ cycles | stable x 3 |
Patient Information
To measure lithium levels in the blood in order to determine the therapeutic level when just starting lithium medication; to monitor levels to ensure they are maintained in the therapeutic range; and sometimes to determine lithium toxicity
When beginning treatment with lithium as the dose is adjusted to achieve therapeutic blood levels; at regular intervals to monitor lithium levels; as needed to detect sub-therapeutic levels or high (toxic) levels
A blood sample drawn from a vein.
No test preparation is needed. However, timing of the sample collection may affect results. Generally, lithium blood levels are measured 12 hours after the last dose (also known as a “trough” level). Tell the person who draws your blood when you took your last dose so that the results can be interpreted correctly.