What is the treatment for antipsychotic-induced Extrapyramidal Symptoms (EPS)?

Treatment for Antipsychotic-Induced Extrapyramidal Symptoms (EPS)

For acute dystonia, immediately administer benztropine 1-2 mg IM/IV, which provides rapid relief within minutes; for drug-induced parkinsonism and akathisia, first reduce the antipsychotic dose or switch to a lower-EPS atypical agent (quetiapine, olanzapine, or clozapine), reserving anticholinergic medications only for significant symptoms when dose reduction fails. 1, 2, 3

Immediate Management by EPS Type

Acute Dystonia (Emergency Treatment)

• Administer benztropine 1-2 mg IM or IV immediately, as this provides quick relief often noticeable within minutes 1, 2
• After initial parenteral treatment, continue benztropine 1-2 mg orally twice daily to prevent recurrence 3
• Young males are at highest risk and require particularly vigilant monitoring 1
• Laryngeal spasm can be life-threatening and requires immediate intervention 4

Drug-Induced Parkinsonism

• First-line strategy: reduce the antipsychotic dose 1
• Second-line strategy: switch to an atypical antipsychotic with lower EPS risk (quetiapine, olanzapine, or clozapine) 1, 5
• If dose reduction and switching fail, add benztropine 1-4 mg once or twice daily 2, 3
• Symptoms typically appear within the first three months of treatment 6

Akathisia

• Reduce the antipsychotic dose as the primary intervention 1
• Switch to a lower-EPS atypical antipsychotic if dose reduction is insufficient 1
• Consider lipophilic beta-blockers (propranolol or metoprolol) as the most effective pharmacological treatment 6
• Benzodiazepines or anticholinergics may be added if beta-blockers are contraindicated 6
• This condition is frequently misinterpreted as anxiety or psychotic agitation, leading to inappropriate dose increases 1

Anticholinergic Medication Guidelines

When to Use Anticholinergics

• Reserve anticholinergics for treatment of significant symptoms only after dose reduction and switching strategies have failed 1
• Do not use anticholinergics routinely for EPS prevention 1
• The recommended dose range for benztropine is 1-4 mg once or twice daily for drug-induced extrapyramidal disorders 2, 3
• Prophylactic anticholinergic therapy is indicated only in high-risk patients (young males starting high-potency typical antipsychotics) 7

Duration of Anticholinergic Treatment

• When EPS develop soon after antipsychotic initiation, they are likely transient 2, 3
• After 1-2 weeks of benztropine treatment, attempt withdrawal to determine continued need 2, 3
• If prophylactic anticholinergic treatment is initiated, discontinue it at least two weeks after initiation 7
• Long-term anticholinergic use is not therapeutically beneficial, and gradual withdrawal typically does not produce EPS recurrence 7
• Maintain anticholinergics even after antipsychotic discontinuation to prevent delayed symptom emergence 1

Anticholinergic Side Effects

• Benztropine can cause delirium, drowsiness, and paradoxical agitation 1
• These adverse effects add to the patient's health burden when used unnecessarily 7

Antipsychotic Selection and Dosing Strategy

Hierarchy of EPS Risk (Lowest to Highest)

• Quetiapine (lowest EPS risk) 5
• Aripiprazole 5
• Olanzapine 5, 8
• Risperidone (highest among atypicals, especially >2 mg/day) 1, 5
• High-potency typical antipsychotics like haloperidol (highest overall risk) 1, 5

Dose-Dependent EPS Prevention

• Use the lowest effective antipsychotic dose 1, 6
• In first-episode psychosis, use maximum 4-6 mg haloperidol equivalent 1
• Increase doses only at widely spaced intervals (14-21 days after initial titration) if response is inadequate 1
• For risperidone, EPS risk increases significantly above 2 mg/day in elderly patients and above 6 mg/day in general 1, 5
• Avoid rapid dose escalation 1

Monitoring Requirements

• Conduct regular monitoring for early EPS signs rather than using prophylactic anticholinergics 1
• Use the Abnormal Involuntary Movement Scale (AIMS) at baseline and every 3-6 months for patients on antipsychotics 4
• Assess level of consciousness, facial movements, oral movements, extremity movements, and trunk movements 4
• Document baseline movement status before medication initiation 4

Critical Clinical Pitfalls

• Avoid misinterpreting akathisia as psychotic agitation or anxiety, which leads to inappropriate antipsychotic dose increases rather than reduction 1
• Do not routinely prescribe prophylactic anticholinergics, as only a segment of patients develop EPS, and unnecessary anticholinergic use adds side effect burden 7
• Certain slowly-developing drug-induced extrapyramidal disorders may not respond to benztropine 2, 3
• Higher-than-recommended atypical antipsychotic doses (e.g., risperidone 8-10 mg, olanzapine 30-40 mg, quetiapine 1200-1500 mg daily) significantly increase EPS risk 7
• Combinations of typical and atypical antipsychotics increase EPS incidence 7