What are the considerations for using lithium in patients with Tardive Dyskinesia (TD)?

Lithium Use in Patients with Tardive Dyskinesia

Lithium should be used with caution in patients with tardive dyskinesia (TD), as it has been reported to both potentially protect against TD in some cases and paradoxically cause or worsen TD-like symptoms in others. 1, 2, 3, 4

Relationship Between Lithium and TD

Potential Protective Effects

• Some evidence suggests lithium may have neuroprotective properties that could reduce TD severity
• A nine-year follow-up study found that lithium use was associated with:
  • Reduced severity of existing TD (2.3-2.9 point reduction on AIMS scale)
  • Lower risk of developing new abnormal movements 3

Potential Risks

• Case reports document lithium monotherapy-induced TD or TD-like syndromes, even at low doses (600mg/day) 2, 4
• Lithium has also been reported to cause tardive dystonia, an uncommon form of chronic dystonia 5
• Some studies show lithium added to neuroleptic treatment did not significantly improve TD 6

Monitoring Recommendations

When using lithium in patients with or at risk for TD:

1. Baseline Assessment

   • Document baseline abnormal movements before starting lithium therapy 1
   • Complete thorough laboratory assessment including:
     • Complete blood cell counts
     • Thyroid function tests
     • Urinalysis
     • Blood urea nitrogen, creatinine, and serum calcium levels 7

2. Regular Monitoring

   • Assess TD symptoms using the Abnormal Involuntary Movement Scale (AIMS) every 3-6 months 1
   • Monitor lithium levels, renal and thyroid function every 3-6 months 7
   • Watch for emergence or worsening of movement disorders 1

3. Dose Considerations

   • Consider dose-dependent relationship - TD symptoms may be reversible with dose reduction 2
   • If TD symptoms emerge or worsen, consider reducing lithium dose while maintaining therapeutic effect 2

Management Strategies

If TD develops or worsens in a patient on lithium:

1. First-line approach:

   • Consider VMAT2 inhibitors (valbenazine or deutetrabenazine) as first-line treatment for TD while maintaining appropriate mood stabilization 1
   • Evaluate if lithium dose reduction is possible while maintaining mood stability 2

2. Alternative mood stabilizers:

   • Consider switching to alternative mood stabilizers if clinically appropriate:
     • Valproate
     • Lamotrigine
     • Carbamazepine 1

3. Avoid medications that may worsen TD:

   • Anticholinergics (benztropine, trihexyphenidyl) should be avoided as they may worsen TD symptoms 1
   • If anticholinergics are being used, taper slowly over 1-2 weeks rather than abruptly discontinuing 1

Risk-Benefit Assessment

When considering lithium in patients with TD:

• Balance the risk of TD against the risk of mood disorder relapse, which can occur with lithium discontinuation 1
• Consider the patient's response to lithium and availability of alternative mood stabilizers
• Weigh the potential neuroprotective effects against the risk of worsening or inducing TD

Special Considerations

• Elderly patients: Higher risk for both TD and lithium toxicity; may need lower doses and more frequent monitoring 1
• Concomitant medications: Avoid combining lithium with antiarrhythmic drugs due to potential cardiac effects 7
• Medication adjustments: If antipsychotics are necessary, consider those with lower TD risk (e.g., quetiapine) 1

Remember that TD management requires careful balancing of psychiatric symptom control with movement disorder management, with regular reassessment of the treatment approach as the patient's condition evolves.