How to manage Extrapyramidal Symptoms (EPS)?

Management of Extrapyramidal Symptoms (EPS)

Immediately discontinue or reduce the dose of the offending antipsychotic medication, and initiate anticholinergic therapy with benztropine 1-2 mg orally or parenterally for acute dystonic reactions, or trihexyphenidyl 1 mg initially for drug-induced parkinsonism, with dose titration based on symptom response. 1, 2

Immediate Assessment and Acute Management

Identify the Type of EPS

• Acute dystonic reactions (muscle spasms, torticollis, oculogyric crisis) require immediate treatment with benztropine 1-2 mL injection, which usually relieves the condition quickly 1
• Drug-induced parkinsonism (bradykinesia, rigidity, tremor) should be treated with benztropine 1-4 mg once or twice daily or trihexyphenidyl starting at 1 mg daily 1, 2
• Akathisia (motor restlessness) and tardive dyskinesia (involuntary movements) represent distinct EPS subtypes that may require different management strategies 3, 4

Acute Dystonic Reaction Protocol

• Administer benztropine 1-2 mL parenterally for rapid relief of acute dystonia 1
• After acute treatment, continue benztropine tablets 1-2 mg twice daily to prevent recurrence 1
• If extrapyramidal disorders develop soon after initiating neuroleptic therapy, they are likely transient; benztropine 1-2 mg two or three times daily usually provides relief within 1-2 days 1
• After 1-2 weeks of symptom control, attempt withdrawal to determine continued need 1

Medication Adjustment Strategy

Primary Intervention: Reduce or Switch Antipsychotic

• Atypical antipsychotics cause significantly fewer EPS than typical antipsychotics (12% vs 46% incidence), making them first-line therapy 5
• When EPS occur with typical antipsychotics, temporarily reduce the tranquilizer dosage while instituting anticholinergic therapy, then adjust both drugs until desired effect is achieved without EPS 2
• Patients with EPS have significantly more negative symptoms and poorer functional outcomes, emphasizing the importance of prevention 5

Anticholinergic Dosing Protocols

For Drug-Induced Parkinsonism:

• Benztropine: 1-4 mg once or twice daily (oral or parenteral), individualized to patient need 1
• Trihexyphenidyl: Start with 1 mg on day one, increase by 2 mg increments every 3-5 days until total of 6-10 mg daily is reached 2
• Total daily trihexyphenidyl dose typically ranges 5-15 mg, though some reactions are controlled with as little as 1 mg daily 2
• Divide high doses (>10 mg daily) into 4 parts: 3 doses at mealtimes and one at bedtime 2

Special Considerations:

• Older patients and thin patients cannot tolerate large doses and require lower starting doses 1
• Postencephalitic patients usually need larger doses (up to 12-15 mg daily) and tolerate them well 1, 2
• Some patients obtain greatest relief with entire dose at bedtime, while others require divided doses 2-4 times daily 1

Long-Term Management and Monitoring

Maintenance Therapy

• After EPS remain controlled for several days, attempt to maintain patients on reduced anticholinergic dosage 2
• Some reactions remain in remission for long periods after anticholinergic therapy is discontinued 2
• Certain slowly developing drug-induced extrapyramidal disorders may not respond to benztropine 1

Prevention Strategy

• Use atypical antipsychotics as first-line therapy to minimize EPS risk, as they are associated with lower relapse rates and improved compliance 6
• Atypical antipsychotics have significantly diminished risk of acute EPS at recommended dose ranges 3
• High doses of atypical antipsychotics can still cause EPS, so maintain dosing within recommended ranges 3

Critical Warnings

Avoid Abrupt Withdrawal

• Never abruptly withdraw anticholinergic treatment as this may result in acute exacerbation of parkinsonian symptoms 2
• Abrupt withdrawal may result in neuroleptic malignant syndrome (NMS) 2

When Combining with Other Medications

• When using anticholinergics concomitantly with levodopa, reduce the usual dose of each medication and carefully adjust based on side effects and symptom control 2
• Anticholinergic dosage of 3-6 mg daily in divided doses is usually adequate when combined with levodopa 2
• When benztropine is started, do not terminate other antiparkinsonian agents abruptly; if reducing or discontinuing, do so gradually 1

Monitoring for Treatment Failure

• EPS are a cause of treatment failure in at least 30% of patients on typical antipsychotics 5
• EPS emergence significantly compromises patient compliance and has profound effects on long-term outcomes 6
• Use standardized scales (ESRS or YESS) to systematically assess occurrence and severity of EPS 4, 7