Lithium level
Blood serum concentration of lithium carbonate measured to ensure therapeutic efficacy and prevent toxicity.
Full Definition
Lithium level refers to the measurement of lithium concentration in blood serum, typically expressed in mEq/L or mmol/L. Regular monitoring is essential due to lithium's narrow therapeutic window, with therapeutic levels generally ranging from 0.6-1.2 mEq/L for maintenance therapy. Levels above 1.5 mEq/L increase toxicity risk, while levels below 0.6 mEq/L may be subtherapeutic. Blood draws should be taken 12 hours after the last dose for accurate measurement. Clinical documentation must include timing of last dose, current dosage, and any symptoms suggesting toxicity or inadequate response.
Usage
Usage note: Always specify timing of blood draw relative to last dose. Use mEq/L as standard unit.
In Context
- "Lithium level drawn 12 hours post-dose was 0.8 mEq/L, within therapeutic range." — Laboratory report
- "Patient requires weekly lithium levels during dose titration phase." — Medication monitoring plan