What is tardive dyskinesia and how is it managed?

Tardive Dyskinesia: Understanding and Management

Tardive dyskinesia is an involuntary movement disorder characterized by repetitive, purposeless movements primarily affecting the face and extremities, caused by long-term use of antipsychotic medications, which should be treated with VMAT2 inhibitors (valbenazine or deutetrabenazine) when moderate to severe. 1

What is Tardive Dyskinesia?

Tardive dyskinesia (TD) is a medication-induced movement disorder that develops after prolonged exposure to dopamine receptor blocking agents, primarily antipsychotic medications. The condition is characterized by:

• Orofacial movements: Repetitive tongue movements, tongue protrusion, chewing movements, facial grimacing, excessive blinking, and lip puckering 1
• Extremity movements: Choreic (rapid, irregular) movements of fingers and hands, athetoid (slow, contorted) movements of limbs 1
• Other manifestations: Can present as dystonia (most common), chorea, or rarely ballism 1

Most TD episodes last less than 1 minute in over 98% of patients 1.

Risk Factors

Understanding who is at risk helps with prevention and early detection:

• Duration of treatment: Risk increases with longer exposure to antipsychotics 1
• Cumulative dose: Higher total doses increase risk 1
• Age: Elderly patients have up to 50% risk after 2 years of continuous typical antipsychotic use 1
• Gender: Women are at higher risk 1
• Pre-existing conditions: Intellectual impairment increases risk 1
• Medication type: Higher risk with first-generation (typical) antipsychotics than second-generation (atypical) antipsychotics 2

Diagnosis

TD must be differentiated from other movement disorders as treatments differ:

• Drug-induced parkinsonism: Characterized by rigidity, bradykinesia, and tremor
• Akathisia: Motor restlessness and inability to sit still
• Withdrawal dyskinesia: Similar movements that occur after stopping antipsychotics but typically resolve 3

Management Approach

1. Prevention is Primary

• Use antipsychotics only when clinically indicated
• Prescribe minimum effective doses
• Regularly monitor using Abnormal Involuntary Movement Scale (AIMS) every 3-6 months
• Record baseline abnormal movements before starting antipsychotics 1

2. First-line Management

• Discontinue antipsychotic if clinically feasible 2
  • However, for many patients with serious mental illness, discontinuation may not be possible due to risk of relapse
  • If discontinuation is not possible, consider switching to an antipsychotic with lower TD risk (e.g., clozapine or quetiapine) 2

3. Pharmacological Treatment

For moderate to severe or disabling TD:

• VMAT2 inhibitors (first-line pharmacological treatment) 1:

  • Valbenazine (Ingrezza): FDA-approved for TD

    • Starting dose: 40 mg daily
    • Target dose: 80 mg daily
    • Advantages: Once-daily dosing, rapid onset (within 2 weeks)

  • Deutetrabenazine (Austedo): FDA-approved for TD

    • Effective dose: 24-36 mg/day
    • Administration: Twice-daily with food
    • Requires gradual titration to minimize side effects

Both medications have demonstrated significant reduction in TD symptoms with response rates of 33-50% 1.

4. Alternative Treatments (when VMAT2 inhibitors are unavailable or not tolerated)

• Amantadine
• Clonazepam
• Ginkgo biloba
• Beta-blockers 1

Note: Anticholinergics (benztropine, trihexyphenidyl) should be avoided as they may worsen TD symptoms 1.

5. For Severe Refractory Cases

• Electroconvulsive therapy (ECT) may be considered when medications are ineffective 1

Special Considerations

• Elderly patients: Higher risk for TD; require careful monitoring and lower doses 1
• Hepatic impairment: May contraindicate certain medications like deutetrabenazine 1
• Patients with mood disorders: Balance TD risk against risk of mood disorder relapse 1

Prognosis

TD can be irreversible in some cases, but early intervention improves outcomes:

• TD may remit partially or completely if antipsychotic treatment is withdrawn early 3
• The risk of irreversibility increases with longer duration of symptoms 1
• Early detection and intervention are crucial for better outcomes 4

Understanding tardive dyskinesia and implementing appropriate prevention and management strategies are essential for improving outcomes in patients requiring long-term antipsychotic treatment.