Lithium Treatment Protocol: Starting Dose and Monitoring
For bipolar disorder treatment, the recommended starting dose of lithium (Depekene) is 600 mg three times daily, with subsequent dose adjustments based on serum levels targeting 0.6-1.2 mEq/L, along with regular monitoring of serum lithium levels, renal function, thyroid function, and clinical response. 1, 2
Initial Dosing Strategy
- Starting dose: 600 mg three times daily for acute mania 1
- Alternative starting regimens:
- 300 mg three or four times daily for maintenance therapy 2
- Lower starting doses for elderly patients:
- Age <40 years: 25-35 mmol/day (925-1300 mg/day)
- Age 40-60 years: 20-25 mmol/day (740-925 mg/day)
- Age >60 years: 15-20 mmol/day (550-740 mg/day) 3
- Consider once-daily dosing (preferably evening) with sustained-release formulations to improve tolerability and adherence 4
Target Serum Levels
- Acute mania: 1.0-1.5 mEq/L 1
- Maintenance therapy: 0.6-1.2 mEq/L 1
- Sustained-release formulations: Target upper range (0.8-1.0 mmol/L) 3
- Elderly patients: Consider lower target ranges due to increased sensitivity 1
Monitoring Protocol
Initial Phase (Acute Treatment)
- Serum lithium levels: Twice weekly during acute phase until stabilized 1
- Timing of blood draws: 8-12 hours after the last dose (immediately before next dose) when levels are stable 1
- Clinical assessment: Regular evaluation of symptoms, side effects, and treatment response
Maintenance Phase
- Serum lithium levels: Every 2 months during remission/maintenance 1
- Regular monitoring parameters 2:
- Renal function tests
- Thyroid function tests
- Complete blood count
- Liver function tests
- Weight and BMI
- Blood pressure
- Fasting glucose
- Lipid panel
- Pregnancy tests (when applicable)
Special Considerations
Renal Impairment
- Contraindicated in patients with significant renal insufficiency 5
- Dose adjustment required for patients with mild-moderate renal impairment 3
- Monitor renal function every 6 months or more frequently with dose changes or acute illness 5
Elderly Patients
- Lower starting doses recommended due to decreased clearance with aging 3
- More frequent monitoring of serum levels and side effects 1
- Higher risk of toxicity at serum levels normally tolerated by younger patients 1
Pregnancy
- Increased clearance: Lithium clearance increases by 30-50% during late pregnancy 3
- Potential fetal harm: Consider risks vs. benefits 5
Toxicity Prevention
- Narrow therapeutic index: Toxicity can occur at levels close to therapeutic concentrations 5
- Signs of toxicity: May appear at serum levels of 1.5-2.0 mEq/L (mild, reversible) 6
- Neurological symptoms: May occur at serum levels >2.0 mEq/L 6
- Permanent brain damage: Possible with prolonged intoxication >2.0 mEq/L 6
Common Pitfalls to Avoid
- Inadequate monitoring of serum levels and side effects
- Relying solely on serum levels without clinical assessment 1
- Rapid medication titration increasing risk of side effects
- Dehydration which can increase lithium concentration
- Concomitant NSAID use which can increase lithium levels 5
- Abrupt discontinuation which can increase suicide risk 2
By following this structured approach to lithium dosing and monitoring, clinicians can maximize therapeutic benefits while minimizing risks of this effective but narrow therapeutic index medication.