Lithium - serum
Last updated: Tuesday, 30, March, 2004
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| Item | Process |
|---|---|
| Specimen | 5 mL blood in plain tube; a lithium heparin tube must not be used. |
| Method | Flame emission spectrophotometry, ISE or spectrophotometry. |
| Therapeutic Interval | 0.6-1.2 mmol/L. |
| Application | Monitoring lithium therapy, blood should be drawn 8-12 hours after the last dose. |
| Interpretation | Lithium half-life is 8-20 hours; may be prolonged in renal failure. Toxic level: >1.9 mmol/L (>1.2 mmol/L may be toxic in older patients). When levels are >1.5 mmol/L, lithium therapy should be discontinued and the patient assessed for toxic symptoms. Increased levels may occur in sodium depletion, eg, associated with diuretics. |
| Reference | Mitchell PB. Br J Clin Pharmacol 2001; 52:1 45-54. |