How to manage tardive dyskinesia (involuntary movement disorder) caused by lithium (lithium carbonate) monotherapy?

Management of Tardive Dyskinesia from Lithium Monotherapy

For tardive dyskinesia (TD) caused by lithium monotherapy, the most effective management approach is to reduce the lithium dosage while maintaining therapeutic efficacy, as lithium-induced TD appears to be dose-dependent and potentially reversible. 1

Initial Assessment and Confirmation

• Use the Abnormal Involuntary Movement Scale (AIMS) to document and quantify the severity of TD symptoms 2
• Distinguish TD from other movement disorders such as:
  • Akathisia (restlessness)
  • Withdrawal dyskinesia (temporary movement disorder after medication discontinuation)
  • Drug-induced parkinsonism (which may coexist with TD)

Management Algorithm

Step 1: Lithium Dose Reduction

• Reduce lithium dosage by approximately 50% while maintaining therapeutic levels 1
• Monitor for TD symptom improvement over 2-3 months
• Continue mood disorder monitoring to ensure psychiatric stability is maintained

Step 2: If TD Persists After Dose Reduction

• Consider switching to an alternative mood stabilizer if clinically appropriate
• Options include:
  • Valproate
  • Lamotrigine
  • Carbamazepine

Step 3: For Persistent Symptoms Despite Medication Changes

• Consider VMAT2 inhibitors which have shown efficacy for TD 2:
  • Deutetrabenazine (24-36 mg/day)
  • Tetrabenazine (mean dose 57.9 mg/day)

Evidence for Lithium-Induced TD Management

Recent evidence suggests that lithium-induced TD differs from antipsychotic-induced TD in important ways:

1. Dose-Dependency: A 2022 case report demonstrated that reducing lithium from 1200 mg/day to 600 mg/day led to significant regression of TD symptoms within 3 months while maintaining mood stability 1

2. Potential Reversibility: Unlike antipsychotic-induced TD which is often irreversible, lithium-induced TD may be reversible with dose reduction 1

3. Paradoxical Effects: Interestingly, lithium has shown protective effects against antipsychotic-induced TD in some studies 3, but can rarely cause TD itself when used as monotherapy 4

Monitoring Recommendations

• Perform AIMS assessments every 3-6 months for patients on long-term lithium therapy 2
• Monitor serum lithium levels to ensure they remain within therapeutic range despite dose adjustments
• Document baseline movement assessments before initiating any psychotropic medication 2

Important Caveats

• Avoid anticholinergics (benztropine, trihexyphenidyl) for TD management as they may worsen symptoms 2
• TD risk increases with age, with elderly patients at significantly higher risk 2
• Maintain mood stability as the primary goal while addressing TD symptoms
• Older studies have shown limited benefit of lithium as a treatment for antipsychotic-induced TD 5, highlighting the distinction between lithium as a cause versus treatment for TD

Special Considerations

• For elderly patients (who are at higher risk), consider lower lithium doses from the start of treatment
• Balance the risk of TD against the risk of mood disorder relapse, which can occur with lithium discontinuation 6
• Consider that lithium has been associated with both causing TD (in rare cases) and protecting against TD (in patients on antipsychotics) 3, 4