How to Start Lithium for Bipolar Disorder
Baseline Laboratory Assessment
Before initiating lithium, obtain comprehensive baseline labs including complete blood count, thyroid function tests (TSH, free T4), urinalysis, blood urea nitrogen (BUN), creatinine, serum calcium, and pregnancy test in females of childbearing age 1, 2. These tests identify contraindications and establish baseline organ function before starting therapy 1.
Initial Dosing Strategy
Start lithium at 300 mg three times daily (900 mg/day total) for patients weighing ≥30 kg, or 300 mg twice daily (600 mg/day) for patients <30 kg 1. For augmentation purposes in depression or elderly patients, lower doses of 150-300 mg per day targeting levels of 0.2-0.6 mEq/L are generally adequate 2.
Target Therapeutic Levels
- Acute mania/mixed episodes: Target serum level of 0.8-1.2 mEq/L 1, 2
- Maintenance therapy: Target serum level of 0.6-1.0 mEq/L 1
- Augmentation therapy: Target serum level of 0.2-0.6 mEq/L 2
Monitoring Schedule
Initial Phase (First 4-8 Weeks)
Check lithium levels twice weekly during the acute phase until levels and clinical condition stabilize 1. Draw levels 12 hours after the last dose (trough level) 1. Increase dose by 300 mg weekly until therapeutic levels are achieved or response criteria are met 1.
Maintenance Phase
Monitor lithium levels, renal function (BUN, creatinine), thyroid function (TSH), and urinalysis every 3-6 months once stable 1, 2. This ongoing monitoring is essential because lithium has a narrow therapeutic window and can cause renal and thyroid dysfunction with chronic use 1, 2.
Critical Safety Education
Educate patients and families on early signs of lithium toxicity: fine tremor, nausea, and diarrhea 1. Instruct them to seek immediate medical attention if coarse tremor, confusion, or ataxia develop, as these indicate severe toxicity 1.
Emphasize the importance of maintaining adequate hydration and consistent salt intake, as dehydration and sodium depletion increase lithium levels and toxicity risk 1. Patients should avoid NSAIDs, ACE inhibitors, and thiazide diuretics when possible, as these medications increase lithium levels 1.
Medication Storage and Overdose Prevention
Parents and caregivers must secure lithium and remove access to lethal quantities, particularly in patients with suicidal ideation 1. Lithium overdoses can be fatal 1. Prescribe limited quantities with frequent refills to minimize stockpiling risk, and implement third-party medication supervision for high-risk patients 1.
Combination Therapy Considerations
For severe mania or treatment-resistant cases, combine lithium with an atypical antipsychotic (aripiprazole, risperidone, quetiapine, or olanzapine) from the outset 1, 3. Combination therapy provides superior efficacy compared to monotherapy for both acute symptom control and relapse prevention 1, 3.
If inadequate response occurs after 6-8 weeks at therapeutic lithium levels, add an atypical antipsychotic rather than abandoning lithium 1. The combination of lithium plus an antipsychotic is more effective than either agent alone 1, 3.
Maintenance Therapy Duration
Continue lithium for at least 12-24 months after achieving mood stabilization 1, 2. Some patients require lifelong treatment, particularly those with multiple severe episodes, rapid cycling, or history of serious suicide attempts 1. Withdrawal of lithium dramatically increases relapse risk, with over 90% of noncompliant patients relapsing versus 37.5% of compliant patients 1.
Discontinuation Protocol (If Necessary)
Never discontinue lithium abruptly 1. Taper gradually over 2-4 weeks minimum, reducing by 10-20% of the original dose every 1-2 weeks 1. Slower tapers extending 4-8 weeks may be prudent for patients with history of rapid relapse or severe episodes 1. Monitor closely for rebound mania, which occurs in the majority of patients who stop lithium suddenly 1.
Adjunctive Psychosocial Interventions
Combine lithium therapy with psychoeducation about symptoms, course of illness, treatment options, and the critical importance of medication adherence 1. Cognitive-behavioral therapy and family-focused therapy should accompany pharmacotherapy to improve outcomes, enhance medication supervision, and identify early warning signs 1.
Common Pitfalls to Avoid
- Inadequate trial duration: Lithium requires 1-2 weeks to show therapeutic effects and 4-6 weeks for full assessment 1, 4
- Subtherapeutic dosing: Always verify serum levels rather than assuming dose adequacy 1
- Insufficient monitoring: Failure to monitor renal and thyroid function leads to preventable complications 1
- Premature discontinuation: Stopping lithium before 12-24 months dramatically increases relapse risk 1
- Ignoring drug interactions: NSAIDs, ACE inhibitors, and thiazides significantly increase lithium levels 1
Special Populations
Lithium is FDA-approved for patients age 12 and older for both acute mania and maintenance therapy 1, 2. For elderly patients or those with renal impairment, start with lower doses (150-300 mg/day) and target lower therapeutic ranges (0.4-0.8 mEq/L) 2.
Unique Anti-Suicide Properties
Lithium reduces suicide attempts 8.6-fold and completed suicides 9-fold, an effect independent of its mood-stabilizing properties 1. This makes lithium particularly valuable for patients with suicidal ideation or history of suicide attempts 1.