Lithium is a mood-stabilizing medication commonly prescribed for bipolar disorder and sometimes for depression or schizoaffective disorder.

Monitoring blood levels is essential because lithium has a narrow therapeutic window.

Clinical uses include:

Ensuring drug levels remain within the therapeutic range.

Detecting subtherapeutic levels (risk of relapse or poor symptom control).

Identifying toxic levels (risk of severe side effects).

The test is performed using a blood sample, typically drawn 12 hours after the last dose (trough level).

Analyte: Serum lithium concentration.

Therapeutic Range: ~0.6 – 1.2 mmol/L (varies by lab and clinical context).

Abnormal Findings:

Low levels: May indicate under-dosing, poor compliance, or drug interactions reducing effectiveness.

High levels: Suggest toxicity, which can cause tremors, confusion, seizures, kidney damage, or cardiac arrhythmias.

Clinical Use:

Guides dosage adjustment for safe and effective therapy.

Prevents lithium toxicity.

Supports long-term management of bipolar and mood disorders