Should benztropine (anticholinergic agent) be stopped before starting Austedo (deutetrabenazine) in a patient with tardive dyskinesia (TD)?

Management of Anticholinergic Medication Before Starting Austedo for Tardive Dyskinesia

Benztropine should be discontinued before starting Austedo (deutetrabenazine) for tardive dyskinesia, as anticholinergics may worsen TD symptoms and interfere with treatment efficacy.

Rationale for Discontinuing Benztropine

Anticholinergic medications like benztropine have an important relationship with tardive dyskinesia (TD) that necessitates their discontinuation before initiating VMAT2 inhibitor therapy:

• The American Academy of Neurology explicitly recommends avoiding anticholinergics (benztropine, trihexyphenidyl) as they may worsen TD symptoms 1
• Anticholinergic medications can exacerbate TD symptoms, potentially counteracting the therapeutic effects of Austedo (deutetrabenazine) 2
• When managing medication regimens, guidelines suggest that medications used to manage side effects (like anticholinergics for EPS) should be removed when they are no longer necessary 3

Proper Discontinuation Process

When discontinuing benztropine before starting Austedo:

1. Gradual tapering is essential:

   • Abrupt discontinuation of anticholinergics should be avoided as it may lead to withdrawal symptoms or rebound effects 3, 4
   • Taper benztropine slowly over 1-2 weeks to minimize risk of withdrawal-emergent dyskinesia 4

2. Monitoring during transition:

   • Closely monitor for emergence or worsening of extrapyramidal symptoms during the tapering process
   • Watch for potential withdrawal effects from benztropine, which may include worsening of parkinsonian symptoms

Treatment with Austedo (Deutetrabenazine)

After benztropine discontinuation, Austedo can be initiated:

• Deutetrabenazine (Austedo) is FDA-approved specifically for TD, with effective doses of 24-36 mg/day 1
• Requires twice-daily administration with food and gradual titration to minimize side effects 1
• Has demonstrated significant reduction in TD symptoms as measured by the Abnormal Involuntary Movement Scale (AIMS) 1

Special Considerations

• Unknown indication for benztropine: Since the patient's reason for benztropine use is unknown, assess for other conditions that might have warranted its use (e.g., drug-induced parkinsonism)
• Elderly patient: The 75-year-old patient is at higher risk for TD, with up to 50% developing the condition after 2 years of continuous typical antipsychotic use 1
• Atypical antipsychotic: If the patient requires continued antipsychotic therapy, consider whether the current atypical antipsychotic has the lowest possible TD risk profile

Common Pitfalls to Avoid

1. Misdiagnosing movement disorders: Ensure TD is correctly diagnosed and differentiated from drug-induced parkinsonism, as treatment approaches differ significantly 2

2. Simultaneous medication changes: Avoid changing multiple medications at once; first discontinue benztropine, then start Austedo after benztropine is fully withdrawn

3. Inadequate monitoring: Regular assessment of TD symptoms using the Abnormal Involuntary Movement Scale (AIMS) is recommended during treatment transitions 1

4. Overlooking the anticholinergic burden: Elderly patients are particularly sensitive to anticholinergic side effects, making discontinuation of benztropine beneficial beyond just TD management

By following this approach, you can optimize the patient's treatment for tardive dyskinesia while minimizing risks associated with medication interactions and adverse effects.