How to manage tardive dyskinesia with parkinsonism?

Management of Tardive Dyskinesia with Parkinsonism

When tardive dyskinesia and parkinsonism coexist, gradually withdraw or reduce the offending antipsychotic if clinically feasible, switch to an atypical antipsychotic with lower D2 affinity, and avoid anticholinergic medications as they do not alleviate tardive dyskinesia and may worsen it. 1, 2

Initial Assessment and Medication Review

• Document the severity of both tardive dyskinesia and parkinsonian symptoms using standardized measures like the Abnormal Involuntary Movement Scale (AIMS) before making any changes 1, 3
• Identify all dopamine receptor-blocking agents the patient is currently receiving, including antipsychotics and gastrointestinal medications like metoclopramide 1
• Patients with coexistent TD and parkinsonism typically have later onset of TD symptoms compared to those with TD alone 4

Primary Management Strategy

Gradually taper the offending antipsychotic medication if the patient's psychiatric condition allows 1, 2

• Abrupt withdrawal should be avoided as it may cause acute exacerbation of symptoms and withdrawal dyskinesia 2, 5
• If antipsychotic therapy must continue, switch to an atypical antipsychotic with lower D2 receptor affinity, as these have significantly lower risk of extrapyramidal symptoms 1, 2

Critical Medication Considerations

Do not use anticholinergic medications (such as trihexyphenidyl or benztropine) to treat the tardive dyskinesia component 1

• The American Psychiatric Association explicitly advises against anticholinergics for tardive dyskinesia, as they are indicated only for acute dystonia and drug-induced parkinsonism, not TD 1
• The FDA label for trihexyphenidyl states that "antiparkinsonism agents do not alleviate the symptoms of tardive dyskinesia, and in some instances may aggravate them" 5
• However, if concomitant Parkinson's disease is present alongside TD, anticholinergic therapy may relieve parkinsonian symptoms specifically 5
• There is increased risk for development of tardive dyskinesia during concomitant administration of anticholinergics and neuroleptics 5

Pharmacologic Treatment for Moderate to Severe TD

For patients with moderate to severe or disabling tardive dyskinesia, initiate treatment with a VMAT2 inhibitor (valbenazine or deutetrabenazine) as first-line pharmacotherapy 1

• These are FDA-approved medications specifically for tardive dyskinesia and demonstrate efficacy in class 1 studies 1
• VMAT2 inhibitors work by depleting dopamine and can suppress dyskinetic movements 6

Special Management Scenarios

• If the patient has underlying idiopathic Parkinson's disease that preceded neuroleptic use, symptoms may be controlled by careful use of dopamine depletors combined with levodopa 4
• Levodopa doses may need reduction during concomitant therapy with anticholinergics, as this combination may increase drug-induced involuntary movements 5
• For patients with tardive dystonia specifically, botulinum toxin may be helpful for focal symptoms 6

Common Pitfalls to Avoid

• Do not increase typical neuroleptic doses to suppress TD symptoms, as this creates a vicious cycle—while it may provide short-term suppression, it worsens the underlying problem and increases parkinsonian symptoms 7
• Avoid drug holidays or intermittent withdrawal, as TD intensity may increase significantly with repeated placebo periods, suggesting this strategy is inappropriate for prevention 7
• Do not use metoclopramide long-term in any patient at risk, as it can cause potentially irreversible tardive dyskinesia 1

Monitoring During Treatment

• Reassess both TD and parkinsonian symptoms every 3-6 months using AIMS 1, 3
• Monitor for psychiatric decompensation when reducing or switching antipsychotics 1
• Up to 50% of patients receiving neuroleptics may experience some form of tardive or withdrawal dyskinesia, emphasizing the need for vigilant monitoring 3, 2