Preferred Sample Type
Suitable Specimen Types
- Serum
Sample Processing in Laboratory
Usual
Sample Preparation
Centrifuge specimens
Turnaround Time
1 daySample Stability
Specimens stable at 4ºC for 1 week. Allow specimens to reach room temperature before analysis.
Lithium
General Information
Lithium is a monovalent alkali metal, which is usually absent in the human body. It is used in the treatment of manic depression psychosis. The drug has proven highly effective in its intended use but some clinically significant complications have been associated with its use. Lithium binding to the plasma proteins is less than 10% and its half-life is 7 – 35 hours. It is mainly eliminated from the body by urine (95%)
Lithium has a very narrow therapeutic range. Initial dosing is aimed at between 0.80 to 1.20 mmol/L and the long-term maintenance level is 0.60 to 0.80 mmol/L. The concentration of Lithium in serum during drug therapy is closely monitored, because Lithium is acutely toxic with concentrations that are slightly higher than the above therapeutic range. The therapeutic window may vary depending on whether the patient is being treated for acute mania or receiving prophylactic therapy. Lithium can have a detrimental effect on fluid balance via action in the kidney
Patient Preparation
Collect specimen 12 hours after the last dose
Notes
Contact the lab if urgent. Wait one week after changing dose before measuring lithium. DO NOT use lithium heparin tubes
Reference Range
0.4-1.0 mmol/L
(Source : Pathology Harmony Recommendations)
Ideally aim for 0.5 -0.8 mmol/L for maintainence/elderly patients and up to 1.2 mmol/L in acute mania. The BNF states a therapeutic range of 0.4 to 1.0 mmol/L 12 hours post dose.
Specifications
- EQA Scheme?: Yes
-
EQA Status:
NEQAS