psych.acute-dystonia-eps.v1PRODUCTION

psych.acute-dystonia-eps.v1

Acute Drug-Induced Dystonia & Extrapyramidal Syndromes — acute dystonia (oculogyric crisis / torticollis / trismus / opisthotonos / LARYNGEAL DYSTONIA = airway emergency) vs acute akathisia vs drug-induced parkinsonism after dopamine-antagonist exposure; IV/IM anticholinergic (benztropine 1-2 mg or diphenhydramine 25-50 mg) reversal + airway management if laryngeal + offending-agent management + propranolol-first-line akathisia + parkinsonism dose-reduction; RULE OUT NMS / serotonin syndrome (Pierre Drug Saf 2005 PMID 16180939; van Harten BMJ 1999 PMID 10463905)

psychiatryacutesubacutepediatricadultgeriatric

Hard-required inputs

0 / 7

Care setting:

Encounter flow

12/12 authored

Canonical 12-phase frame with authored status for this dossier.

Current phase

Frame

Detailed

Set the acute drug-induced EPS frame: acute dystonia (incl. LARYNGEAL airway emergency) vs acute akathisia vs drug-induced parkinsonism × causative agent (typical/atypical AP / metoclopramide / prochlorperazine / promethazine / droperidol) × pediatric/young-adult (dystonia risk) vs adult vs elderly (parkinsonism risk) × first-exposure vs dose-escalation — and explicitly NOT NMS / serotonin syndrome / tardive dyskinesia (Pierre Drug Saf 2005 PMID 16180939; van Harten BMJ 1999 PMID 10463905)

Inputs

Actions

Advance rule

Set

Advance when

Phenotype + agent + population + exposure-window hypothesis assigned; NMS/serotonin-syndrome explicitly considered

Patient inputs (12)

offending_dopamine_antagonist*medication • CONTEXT

not present

Causative agent + class + potency + dose + route + exposure timing — high-potency typical antipsychotic (haloperidol) > risperidone > metoclopramide/prochlorperazine > olanzapine > quetiapine/clozapine; first-exposure and dose-escalation are the dystonia windows; the agent drives both reversal and offending-agent management (Pierre Drug Saf 2005 PMID 16180939; van Harten BMJ 1999 PMID 10463905)

age*demographic • CONTEXT

Pediatric + young adult — highest acute-dystonia risk (weight-based benztropine/diphenhydramine dosing); elderly — highest drug-induced-parkinsonism risk + anticholinergic-burden caution (avoid benztropine/diphenhydramine where possible — falls, delirium, urinary retention; AGS Beers 2023); drives agent + dose selection (van Harten BMJ 1999 PMID 10463905; Seitz Drugs Aging 2009)

eps_phenotype*symptom • DIFFERENTIAL

Acute dystonia (sustained posturing — oculogyric / torticollis / trismus / opisthotonos / LARYNGEAL) vs acute akathisia (inner restlessness + pacing) vs drug-induced parkinsonism (bradykinesia + rigidity + tremor) — the phenotype determines the entire treatment branch; laryngeal dystonia is an airway emergency (Pierre Drug Saf 2005 PMID 16180939)

mental_status_and_rigidity_character*symptom • DIFFERENTIAL

Clear sensorium + focal/segmental dystonic posturing → acute dystonia; altered mental status + diffuse lead-pipe rigidity → NMS; clonus + hyperreflexia + serotonergic agent → serotonin syndrome — the pivot that prevents misclassifying a benign reversible EPS as (or missing) a lethal toxidrome (Pierre Drug Saf 2005 PMID 16180939; cross-ref psych.serotonin-syndrome.v1)

medication_reconciliation_full*medication • INITIAL_WORKUP

not present

Full medication reconciliation — identify ALL dopamine antagonists (including occult antiemetics, metoclopramide for gastroparesis, prochlorperazine for migraine, depot antipsychotic) so the true offending agent is not missed; rendered inline (no canonical workup id) (Pierre Drug Saf 2005 PMID 16180939)

laryngeal_airway_involvement*symptom • RED_FLAGS

Stridor / dysphonia / dyspnea / throat-tightening = LARYNGEAL DYSTONIA — life-threatening airway obstruction; mandates immediate IV anticholinergic + airway readiness + escalation; the single most time-critical branch of this engine (van Harten BMJ 1999 PMID 10463905)

temp_hr_bp_for_nms_exclusion*vital • RED_FLAGS

Temperature + HR + BP — acute EPS has NO hyperthermia and NO autonomic instability; fever + autonomic dysregulation + rigidity reframes to NMS (cross-ref psych.neuroleptic-malignant-syndrome.v1), not benign acute EPS (Pierre Drug Saf 2005 PMID 16180939)

prior_eps_or_risk_factorshistory • CONTEXT

not present

Prior acute dystonia (strong recurrence predictor), young male, high-potency D2 antagonist, rapid dose escalation, depot injection, IV-bolus antiemetic, cocaine use, dehydration, hypoparathyroidism — pre-test risk modifiers + recurrence-prevention duration (van Harten BMJ 1999 PMID 10463905)

concurrent_serotonergic_or_anticholinergic_loadmedication • CONTEXT

not present

Concurrent serotonergic agents (serotonin-syndrome differential — cross-ref psych.serotonin-syndrome.v1) + baseline anticholinergic burden (limits additive benztropine/diphenhydramine, esp. elderly — delirium/retention) (Boyer NEJM 2005 PMID 15784664; AGS Beers 2023)

suicidality_aggression_with_akathisiasymptom • DIFFERENTIAL

Akathisia carries a recognized association with suicidality + aggression + treatment non-adherence — screen and cross-route if SI/aggression surfaces (Barnes Br J Psychiatry 1989 PMID 2574607; cross-ref psych.suicidality.ed.core.v1)

ck_to_exclude_nmslab • INITIAL_WORKUP

Creatine kinase — acute dystonia/akathisia/parkinsonism does NOT markedly elevate CK; CK > 1000 (or markedly rising) with rigidity + fever + autonomic instability reframes to NMS (cross-ref psych.neuroleptic-malignant-syndrome.v1); rendered inline (no canonical workup id) (Strawn AJP 2007 PMID 17541055)

ecg_qtc_if_droperidol_contextimaging • INITIAL_WORKUP

not present

ECG/QTc relevant when the offending or substituted agent is QT-prolonging (droperidol/haloperidol/ziprasidone) or when propranolol is used for akathisia (bradycardia/AV block screen) — gates safe agent substitution (Calver Ann Emerg Med 2015 PMID 25920334)

* = hard-required. Engine cannot meaningfully run until these are filled.

Severity triggers (5)

5 need judgement

informationallife_threateninglaryngeal_dystonia_airway_emergency (van Harten BMJ 1999 PMID 10463905)
Laryngeal dystonia — stridor / dysphonia / dyspnea / throat-tightening after a dopamine-antagonist — life-threatening airway obstruction
Trigger could not be auto-evaluated — needs clinician judgement.
informationallife_threateningeps_versus_NMS_or_serotonin_syndrome_pivot (Strawn AJP 2007 PMID 17541055; Boyer NEJM 2005 PMID 15784664)
Movement disorder after a dopamine-antagonist WITH fever / autonomic instability / lead-pipe rigidity / ↑↑CK / AMS (NMS) OR clonus / hyperreflexia / serotonergic agent (serotonin syndrome) — NOT benign acute EPS
Trigger could not be auto-evaluated — needs clinician judgement.
informationalseveregeneralized_acute_dystonia_oculogyric_opisthotonos (Pierre Drug Saf 2005 PMID 16180939)
Generalized / severe acute dystonia — oculogyric crisis, opisthotonos, severe torticollis/retrocollis, trismus, buccolingual crisis — after a dopamine-antagonist, no airway involvement
Trigger could not be auto-evaluated — needs clinician judgement.
informationalsevereacute_akathisia_with_suicidality_or_aggression (Barnes Br J Psychiatry 1989 PMID 2574607)
Acute akathisia with concurrent suicidal ideation, aggression, or treatment non-adherence after starting/escalating a dopamine-antagonist
Trigger could not be auto-evaluated — needs clinician judgement.
informationalmoderatemoderate_akathisia_or_drug_induced_parkinsonism (Pierre Drug Saf 2005 PMID 16180939; Seitz Drugs Aging 2009)
Moderate akathisia without suicidality OR symptomatic drug-induced parkinsonism (bradykinesia + rigidity + tremor) emerging over days-weeks of a dopamine-antagonist
Trigger could not be auto-evaluated — needs clinician judgement.

Workflow calculators

Run this disease's risk and dosing calculators inline.

RISK_STRATIFICATIONoptionalDrives dose adjustment

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Recommended regimen

Acute dystonia reversal — IV/IM anticholinergic (benztropine or diphenhydramine), repeat if needed, benzodiazepine adjunct for refractory; AIRWAY MANAGEMENT + escalate if LARYNGEAL dystonia (van Harten BMJ 1999 PMID 10463905; Pierre Drug Saf 2005 PMID 16180939; Lima Cochrane anticholinergics for acute dystonia PMID 15106194)

axis: acute_dystonia_reversal

Selected axis "Acute dystonia reversal — IV/IM anticholinergic (benztropine or diphenhydramine), repeat if needed, benzodiazepine adjunct for refractory; AIRWAY MANAGEMENT + escalate if LARYNGEAL dystonia (van Harten BMJ 1999 PMID 10463905; Pierre Drug Saf 2005 PMID 16180939; Lima Cochrane anticholinergics for acute dystonia PMID 15106194)" by default fallback (first axis)

benztropine
first line
anticholinergic_antimuscarinic
1-2 mg IV (preferred for speed in laryngeal/severe) or IM (pediatric / elderly dose-reduced 0.5-1 mg) • IV/IM • once; may repeat after 20-30 min if no response (max ~6 mg/24 h acute) (max: ~6 mg/24 h acute; elderly minimise (anticholinergic burden — AGS Beers 2023))
triggers: acute_dystonia_oculogyric_torticollis_trismus_opisthotonos, laryngeal_dystonia_airway_emergency_IV, first_line_anticholinergic_reversal
van Harten BMJ 1999 PMID 10463905 — IV/IM anticholinergic is first-line and usually produces dramatic reversal within minutes (a diagnostic-therapeutic trial); benztropine preferred where less sedation desired; IV route for laryngeal/severe; dose-reduce + minimise in elderly (delirium, urinary retention, falls — AGS Beers 2023)
rxcui 1424
diphenhydramine
first line
first_generation_antihistamine_anticholinergic
25-50 mg IV/IM (pediatric 1 mg/kg IV/IM, max 50 mg; elderly minimise) • IV/IM • once; may repeat after 20-30 min if no response (max: 100 mg/24 h acute; avoid in elderly where possible (AGS Beers 2023))
triggers: acute_dystonia_first_line_alternative, laryngeal_dystonia_airway_emergency_IV, pediatric_acute_dystonia_weight_based
van Harten BMJ 1999 PMID 10463905; Lima Cochrane PMID 15106194 — diphenhydramine IV/IM equally effective first-line anticholinergic for acute dystonia; added sedation can be useful; weight-based in pediatrics (highest-risk group); minimise in elderly + delirium (anticholinergic — AGS Beers 2023)
rxcui 3498
lorazepam
add on
benzodiazepine
1-2 mg IV/IM (elderly 0.5-1 mg) • IV/IM • once; titrate q15-30 min PRN for refractory/recurrent dystonia (max: titrate to resolution; avoid oversedation/respiratory depression)
triggers: refractory_acute_dystonia_after_anticholinergic, severe_generalized_dystonia_opisthotonos, laryngeal_dystonia_adjunct
Pierre Drug Saf 2005 PMID 16180939 — benzodiazepine adjunct for acute dystonia not fully responsive to anticholinergic, or severe generalized/laryngeal cases; muscle relaxation + anxiolysis; not a substitute for anticholinergic
rxcui 6470
airway management + escalation (laryngeal dystonia)
rescue
airway_intervention
For LARYNGEAL dystonia (stridor / dysphonia / dyspnea): immediate IV benztropine/diphenhydramine + high-flow O2 + airway equipment at bedside + senior/anesthesia/ENT alert; prepare for definitive airway if obstruction progresses despite reversal • NA • immediate, continuous until reversed
triggers: laryngeal_dystonia_stridor_dysphonia_dyspnea, airway_compromise_progressing_despite_anticholinergic
van Harten BMJ 1999 PMID 10463905 — laryngeal dystonia is a life-threatening airway emergency; IV anticholinergic usually reverses rapidly but airway readiness + escalation must not be deferred while waiting for response

ed playbook — drug actions (6)

1. airway management first if LARYNGEAL dystonia
Stridor/dysphonia/dyspnea → high-flow O2 + airway equipment + senior/anesthesia/ENT alert concurrent with IV anticholinergic • NA • immediate
trigger: Laryngeal dystonia / airway compromise (van Harten BMJ 1999 PMID 10463905)
Laryngeal dystonia is a life-threatening airway emergency — airway readiness must not be deferred while awaiting reversal (van Harten BMJ 1999 PMID 10463905)
2. IV/IM anticholinergic to reverse acute dystonia
rxcui 1514
Benztropine 1-2 mg IV/IM OR diphenhydramine 25-50 mg IV/IM (pediatric diphenhydramine 1 mg/kg; elderly dose-reduced) • IV/IM • once; repeat after 20-30 min if no response
trigger: Acute dystonia — oculogyric crisis / torticollis / trismus / opisthotonos / laryngeal (van Harten BMJ 1999 PMID 10463905)
IV/IM anticholinergic produces dramatic reversal within minutes — a diagnostic-therapeutic trial (van Harten BMJ 1999 PMID 10463905; Lima Cochrane PMID 15106194)
3. benzodiazepine adjunct for refractory/severe dystonia
rxcui 6470
Lorazepam 1-2 mg IV/IM (elderly 0.5-1 mg) • IV/IM • once; titrate PRN
trigger: Dystonia not fully responsive to anticholinergic, or severe generalized/laryngeal (Pierre Drug Saf 2005 PMID 16180939)
Benzodiazepine adjunct adds muscle relaxation + anxiolysis for refractory acute dystonia (Pierre Drug Saf 2005 PMID 16180939)
4. exclude NMS / serotonin syndrome before attributing to benign EPS
Temperature + autonomic + rigidity character + CK; clonus/hyperreflexia + serotonergic agent screen • NA • concurrent
trigger: Any movement disorder after a dopamine antagonist (Pierre Drug Saf 2005 PMID 16180939)
Acute EPS has no fever/autonomic instability/↑↑CK/clonus — these reframe to NMS or serotonin syndrome (Strawn AJP 2007 PMID 17541055; Boyer NEJM 2005 PMID 15784664)
5. manage offending agent + recurrence prevention
rxcui 1514
Stop/reduce/switch the dopamine antagonist (lower-EPS-risk option; ondansetron for antiemetic cause) + oral benztropine 1-2 mg BID 24-72 h • PO • once + 24-72 h
trigger: After acute dystonia reversed (van Harten BMJ 1999 PMID 10463905)
Dystonia recurs as parenteral anticholinergic wears off if offending agent continues — definitive treatment is removing/reducing it (van Harten BMJ 1999 PMID 10463905)
6. akathisia: propranolol first-line; parkinsonism: amantadine/anticholinergic
rxcui 8787
Akathisia → propranolol 10-20 mg TID (± benzodiazepine; mirtazapine 15 mg alt) + screen suicidality; parkinsonism → amantadine 100 mg BID (elderly) or anticholinergic + agent change • PO • per phenotype
trigger: Akathisia or drug-induced parkinsonism phenotype (Lima Cochrane PMID 15495018; Seitz Drugs Aging 2009)
Propranolol best-supported first-line for akathisia; amantadine preferred over anticholinergic for parkinsonism in elderly (Lima Cochrane PMID 15495018; Pierre Drug Saf 2005 PMID 16180939)

Auto-drafted A&P note

Subjective

- Possible entry pathways: Acute sustained involuntary posturing — oculogyric crisis, torticollis/retrocollis, trismus, buccolingual crisis, opisthotonos — within hours-to-days of a dopamine-antagonist (antipsychotic / metoclopramide / prochlorperazine / promethazine / droperidol); first-exposure or dose-escalation (van Harten BMJ 1999 PMID 10463905; Pierre Drug Saf 2005 PMID 16180939); Stridor / dysphonia / dyspnea / sense of throat tightening after a dopamine-antagonist — LARYNGEAL DYSTONIA: airway emergency requiring immediate IV anticholinergic + airway management (van Harten BMJ 1999 PMID 10463905; Pierre Drug Saf 2005 PMID 16180939); Subjective inner restlessness + objective pacing / leg-crossing-uncrossing / inability to sit still after starting/escalating an antipsychotic or antiemetic — acute AKATHISIA (suicidality + aggression association — re-screen) (Barnes Br J Psychiatry 1989 PMID 2574607; Drotts Ann Emerg Med 1999 PMID 10499951).

Objective

- No vitals, labs, or imaging entered for this encounter.

Assessment

**Acute Drug-Induced Dystonia & Extrapyramidal Syndromes — acute dystonia (oculogyric crisis / torticollis / trismus / opisthotonos / LARYNGEAL DYSTONIA = airway emergency) vs acute akathisia vs drug-induced parkinsonism after dopamine-antagonist exposure; IV/IM anticholinergic (benztropine 1-2 mg or diphenhydramine 25-50 mg) reversal + airway management if laryngeal + offending-agent management + propranolol-first-line akathisia + parkinsonism dose-reduction; RULE OUT NMS / serotonin syndrome (Pierre Drug Saf 2005 PMID 16180939; van Harten BMJ 1999 PMID 10463905)** (psych.acute-dystonia-eps.v1).
Phenotype framing: Acute dystonia (clear sensorium + sustained focal/segmental posturing, rapid anticholinergic reversal — LR+ high) vs akathisia (inner restlessness + pacing, normal tone) vs drug-induced parkinsonism (bradykinesia + rigidity + tremor, insidious) — all distinguished from NMS (fever + autonomic instability + diffuse lead-pipe rigidity + ↑↑CK + AMS) and serotonin syndrome (clonus + hyperreflexia + serotonergic agent + hyperthermia); akathisia screens for suicidality/aggression (Pierre Drug Saf 2005 PMID 16180939; Barnes Br J Psychiatry 1989 PMID 2574607)
Scope: Set the acute drug-induced EPS frame: acute dystonia (incl. LARYNGEAL airway emergency) vs acute akathisia vs drug-induced parkinsonism × causative agent (typical/atypical AP / metoclopramide / prochlorperazine / promethazine / droperidol) × pediatric/young-adult (dystonia risk) vs adult vs elderly (parkinsonism risk) × first-exposure vs dose-escalation — and explicitly NOT NMS / serotonin syndrome / tardive dyskinesia (Pierre Drug Saf 2005 PMID 16180939; van Harten BMJ 1999 PMID 10463905)

No severity triggers fired against current inputs.

Plan

Regimen axis: **Acute dystonia reversal — IV/IM anticholinergic (benztropine or diphenhydramine), repeat if needed, benzodiazepine adjunct for refractory; AIRWAY MANAGEMENT + escalate if LARYNGEAL dystonia (van Harten BMJ 1999 PMID 10463905; Pierre Drug Saf 2005 PMID 16180939; Lima Cochrane anticholinergics for acute dystonia PMID 15106194)**.
1. benztropine 1-2 mg IV (preferred for speed in laryngeal/severe) or IM (pediatric / elderly dose-reduced 0.5-1 mg) IV/IM once; may repeat after 20-30 min if no response (max ~6 mg/24 h acute) (anticholinergic_antimuscarinic, first line) — van Harten BMJ 1999 PMID 10463905 — IV/IM anticholinergic is first-line and usually produces dramatic reversal within minutes (a diagnostic-therapeutic trial); benztropine preferred where less sedation desired; IV route for laryngeal/severe; dose-reduce + minimise in elderly (delirium, urinary retention, falls — AGS Beers 2023)
2. diphenhydramine 25-50 mg IV/IM (pediatric 1 mg/kg IV/IM, max 50 mg; elderly minimise) IV/IM once; may repeat after 20-30 min if no response (first_generation_antihistamine_anticholinergic, first line) — van Harten BMJ 1999 PMID 10463905; Lima Cochrane PMID 15106194 — diphenhydramine IV/IM equally effective first-line anticholinergic for acute dystonia; added sedation can be useful; weight-based in pediatrics (highest-risk group); minimise in elderly + delirium (anticholinergic — AGS Beers 2023)
3. lorazepam 1-2 mg IV/IM (elderly 0.5-1 mg) IV/IM once; titrate q15-30 min PRN for refractory/recurrent dystonia (benzodiazepine, add on) — Pierre Drug Saf 2005 PMID 16180939 — benzodiazepine adjunct for acute dystonia not fully responsive to anticholinergic, or severe generalized/laryngeal cases; muscle relaxation + anxiolysis; not a substitute for anticholinergic
4. airway management + escalation (laryngeal dystonia) For LARYNGEAL dystonia (stridor / dysphonia / dyspnea): immediate IV benztropine/diphenhydramine + high-flow O2 + airway equipment at bedside + senior/anesthesia/ENT alert; prepare for definitive airway if obstruction progresses despite reversal NA immediate, continuous until reversed (airway_intervention, rescue) — van Harten BMJ 1999 PMID 10463905 — laryngeal dystonia is a life-threatening airway emergency; IV anticholinergic usually reverses rapidly but airway readiness + escalation must not be deferred while waiting for response

Setting playbook (ed) — Recognize the acute drug-induced extrapyramidal syndrome, immediately reverse acute dystonia with IV/IM anticholinergic (secure the airway first if LARYNGEAL), explicitly exclude NMS and serotonin syndrome, manage the offending agent, and disposition with a recurrence-prevention plan + ADR documentation (Pierre Drug Saf 2005 PMID 16180939; van Harten BMJ 1999 PMID 10463905)
5. airway management first if LARYNGEAL dystonia Stridor/dysphonia/dyspnea → high-flow O2 + airway equipment + senior/anesthesia/ENT alert concurrent with IV anticholinergic NA immediate — Laryngeal dystonia / airway compromise (van Harten BMJ 1999 PMID 10463905) (Laryngeal dystonia is a life-threatening airway emergency — airway readiness must not be deferred while awaiting reversal (van Harten BMJ 1999 PMID 10463905))
6. IV/IM anticholinergic to reverse acute dystonia Benztropine 1-2 mg IV/IM OR diphenhydramine 25-50 mg IV/IM (pediatric diphenhydramine 1 mg/kg; elderly dose-reduced) IV/IM once; repeat after 20-30 min if no response — Acute dystonia — oculogyric crisis / torticollis / trismus / opisthotonos / laryngeal (van Harten BMJ 1999 PMID 10463905) (IV/IM anticholinergic produces dramatic reversal within minutes — a diagnostic-therapeutic trial (van Harten BMJ 1999 PMID 10463905; Lima Cochrane PMID 15106194))
7. benzodiazepine adjunct for refractory/severe dystonia Lorazepam 1-2 mg IV/IM (elderly 0.5-1 mg) IV/IM once; titrate PRN — Dystonia not fully responsive to anticholinergic, or severe generalized/laryngeal (Pierre Drug Saf 2005 PMID 16180939) (Benzodiazepine adjunct adds muscle relaxation + anxiolysis for refractory acute dystonia (Pierre Drug Saf 2005 PMID 16180939))
8. exclude NMS / serotonin syndrome before attributing to benign EPS Temperature + autonomic + rigidity character + CK; clonus/hyperreflexia + serotonergic agent screen NA concurrent — Any movement disorder after a dopamine antagonist (Pierre Drug Saf 2005 PMID 16180939) (Acute EPS has no fever/autonomic instability/↑↑CK/clonus — these reframe to NMS or serotonin syndrome (Strawn AJP 2007 PMID 17541055; Boyer NEJM 2005 PMID 15784664))
9. manage offending agent + recurrence prevention Stop/reduce/switch the dopamine antagonist (lower-EPS-risk option; ondansetron for antiemetic cause) + oral benztropine 1-2 mg BID 24-72 h PO once + 24-72 h — After acute dystonia reversed (van Harten BMJ 1999 PMID 10463905) (Dystonia recurs as parenteral anticholinergic wears off if offending agent continues — definitive treatment is removing/reducing it (van Harten BMJ 1999 PMID 10463905))
10. akathisia: propranolol first-line; parkinsonism: amantadine/anticholinergic Akathisia → propranolol 10-20 mg TID (± benzodiazepine; mirtazapine 15 mg alt) + screen suicidality; parkinsonism → amantadine 100 mg BID (elderly) or anticholinergic + agent change PO per phenotype — Akathisia or drug-induced parkinsonism phenotype (Lima Cochrane PMID 15495018; Seitz Drugs Aging 2009) (Propranolol best-supported first-line for akathisia; amantadine preferred over anticholinergic for parkinsonism in elderly (Lima Cochrane PMID 15495018; Pierre Drug Saf 2005 PMID 16180939))

Non-pharmacologic actions:
- Airway equipment + anesthesia/ENT activation at bedside for laryngeal dystonia (van Harten BMJ 1999 PMID 10463905)
- Continuous SpO2 + cardiac monitoring if laryngeal involvement or parenteral benzodiazepine given
- Document the offending agent as an adverse drug reaction / allergy-list entry + prescriber communication (Pierre Drug Saf 2005 PMID 16180939)
- Patient education on early dystonia recognition + return precautions (van Harten BMJ 1999 PMID 10463905)
- Cross-route to psych.neuroleptic-malignant-syndrome.v1 / psych.serotonin-syndrome.v1 if hyperthermic-toxidrome features; psych.suicidality.ed.core.v1 if akathisia + SI; psych.agitation-ed.v1 if the EPS arose during chemical-restraint

AVOID / contraindication checks:
- Laryngeal_dystonia_is_an_airway_emergency_IV_anticholinergic_plus_airway_readiness_immediately (van Harten BMJ 1999 PMID 10463905)
- Exclude_NMS_before_attributing_to_benign_acute_dystonia_no_fever_no_autonomic_instability_no_markedly_elevated_CK (Pierre Drug Saf 2005 PMID 16180939; cross ref psych.neuroleptic malignant syndrome.v1)
- Anticholinergic_dose_reduce_and_minimise_in_elderly_delirium_urinary_retention_falls (AGS Beers 2023)
- Do_not_delay_IV_IM_anticholinergic_reversal_of_acute_dystonia_for_labs_or_imaging (van Harten BMJ 1999 PMID 10463905)
- Benzodiazepine_adjunct_watch_respiratory_depression_especially_with_laryngeal_involvement (Pierre Drug Saf 2005 PMID 16180939)

Monitoring

Regimen monitoring:
- Observe for reversal within minutes of IV anticholinergic diagnostic therapeutic trial (van Harten BMJ 1999 PMID 10463905)
- Continuous SpO2 and airway watch until resolved if laryngeal involvement (van Harten BMJ 1999 PMID 10463905)
- Observe at least 4 6 h for rebound dystonia as IV anticholinergic half life wanes (Pierre Drug Saf 2005 PMID 16180939)
- Reassess for NMS if fever rigidity autonomic instability or rising CK emerge (Strawn AJP 2007 PMID 17541055; cross-ref psych.neuroleptic-malignant-syndrome.v1)

Setting (ed) monitoring:
- Observe reversal within minutes of IV anticholinergic; observe ≥ 4-6 h for rebound dystonia (Pierre Drug Saf 2005 PMID 16180939)
- Continuous SpO2 + airway watch until laryngeal dystonia fully resolved (van Harten BMJ 1999 PMID 10463905)
- Serial Barnes scale + suicidality re-screen for akathisia (Barnes Br J Psychiatry 1989 PMID 2574607)
- Reassess for emergent NMS (fever + rigidity + autonomic instability + rising CK) on any continued antipsychotic (Strawn AJP 2007 PMID 17541055)
- Serial motor exam over weeks-months for parkinsonism resolution off agent (Seitz Drugs Aging 2009)

Follow-up plan: Document the offending agent as an adverse drug reaction / allergy-list entry; communicate the EPS-risk to prescribers; choose a lower-EPS-risk agent for ongoing psychiatric need (route disease-specific engine); akathisia → psychiatric follow-up + adherence support; parkinsonism → confirm resolution off agent vs unmasked idiopathic PD (neurology); patient education on early dystonia recognition + return precautions (Pierre Drug Saf 2005 PMID 16180939; Seitz Drugs Aging 2009)
- Close-out criterion: Offending agent documented as ADR + lower-EPS-risk plan arranged + phenotype-directed follow-up set + cross-route dossiers engaged

Monitoring phase: Acute dystonia — observe ≥ 4-6 h for response + rebound after IV anticholinergic half-life wanes (recurrence common — continue oral anticholinergic 24-72 h, longer if offending agent continued). Laryngeal — continuous SpO2 + airway watch until fully resolved. Akathisia — serial Barnes scale + suicidality re-screen. Parkinsonism — serial exam over weeks for resolution after agent change; persistence > 3-6 months suggests unmasked idiopathic PD. Watch for emergent NMS (fever/rigidity/↑CK) on any continued antipsychotic (Pierre Drug Saf 2005 PMID 16180939; Barnes Br J Psychiatry 1989 PMID 2574607)

Disposition

Current setting: ed — Recognize the acute drug-induced extrapyramidal syndrome, immediately reverse acute dystonia with IV/IM anticholinergic (secure the airway first if LARYNGEAL), explicitly exclude NMS and serotonin syndrome, manage the offending agent, and disposition with a recurrence-prevention plan + ADR documentation (Pierre Drug Saf 2005 PMID 16180939; van Harten BMJ 1999 PMID 10463905)

Disposition criteria:
- Laryngeal dystonia → ED resuscitation/observation with airway readiness until fully reversed; admit if recurrent or airway-threatened (van Harten BMJ 1999 PMID 10463905)
- Generalized acute dystonia → observe until reversed + recurrence-prevention anticholinergic + offending-agent plan, then discharge with return precautions
- Akathisia with suicidality → cross-route psych.suicidality.ed.core.v1 + psychiatric disposition
- Drug-induced parkinsonism → outpatient with agent change + monitored resolution; neurology if persistent/asymmetric
- All: offending agent documented as ADR + lower-EPS-risk plan communicated to prescribers before disposition (Pierre Drug Saf 2005 PMID 16180939)

Escalation triggers (move to higher acuity):
- Laryngeal dystonia with airway compromise progressing despite IV anticholinergic → definitive airway + ICU (van Harten BMJ 1999 PMID 10463905)
- Fever + autonomic instability + lead-pipe rigidity + ↑↑CK + AMS → cross-route psych.neuroleptic-malignant-syndrome.v1 (Strawn AJP 2007 PMID 17541055)
- Clonus + hyperreflexia + hyperthermia on serotonergic agents → cross-route psych.serotonin-syndrome.v1 (Boyer NEJM 2005 PMID 15784664)
- Akathisia with suicidal ideation / aggression → cross-route psych.suicidality.ed.core.v1 (Barnes Br J Psychiatry 1989 PMID 2574607; VA/DoD 2022)
- Atypical / persistent / asymmetric movement disorder not reversing with anticholinergic → neurology evaluation (seizure / structural / tetanus / primary dystonia)

Earlier-Return Triggers

Return-precaution thresholds (watch for):
- [LIFE_THREATENING] Laryngeal dystonia — stridor / dysphonia / dyspnea / throat-tightening after a dopamine-antagonist — life-threatening airway obstruction
- [LIFE_THREATENING] Movement disorder after a dopamine-antagonist WITH fever / autonomic instability / lead-pipe rigidity / ↑↑CK / AMS (NMS) OR clonus / hyperreflexia / serotonergic agent (serotonin syndrome) — NOT benign acute EPS
- [SEVERE] Generalized / severe acute dystonia — oculogyric crisis, opisthotonos, severe torticollis/retrocollis, trismus, buccolingual crisis — after a dopamine-antagonist, no airway involvement

Citations

- Acute drug-induced extrapyramidal syndromes — Pierre JM Drug Saf 2005 PMID 16180939 (extrapyramidal side effects of antipsychotics: recognition + acute management) + van Harten PN BMJ 1999 PMID 10463905 (acute dystonia clinical review + anticholinergic reversal) + Cochrane systematic reviews (Lima — anticholinergics for acute dystonia PMID 15106194; propranolol/beta-blockers for acute akathisia PMID 15495018; benzodiazepines for acute akathisia PMID 11034738) + Poyurovsky Br J Psychiatry 2001 PMID 11581110 (mirtazapine for akathisia) + Barnes Br J Psychiatry 1989 PMID 2574607 (Barnes Akathisia Rating Scale) + ED-antiemetic-EPS evidence (Drotts Ann Emerg Med 1999 PMID 10499951; Vinson Ann Emerg Med 2001 PMID 11574794) + Caroff J Clin Psychiatry 2002 PMID 12562137 (movement-disorder spectrum) — explicitly distinguished from NMS (Strawn AJP 2007 PMID 17541055) and serotonin syndrome (Boyer NEJM 2005 PMID 15784664) [PMID:16180939](https://pubmed.ncbi.nlm.nih.gov/16180939/)
- Cited evidence (PMID 10463905) [PMID:10463905](https://pubmed.ncbi.nlm.nih.gov/10463905/)
- Cited evidence (PMID 15106194) [PMID:15106194](https://pubmed.ncbi.nlm.nih.gov/15106194/)
- Cited evidence (PMID 15495018) [PMID:15495018](https://pubmed.ncbi.nlm.nih.gov/15495018/)
- Cited evidence (PMID 11034738) [PMID:11034738](https://pubmed.ncbi.nlm.nih.gov/11034738/)

Last reconciled with current guidelines: 2026-05-15.

References

Acute drug-induced extrapyramidal syndromes — Pierre JM Drug Saf 2005 PMID 16180939 (extrapyramidal side effects of antipsychotics: recognition + acute management) + van Harten PN BMJ 1999 PMID 10463905 (acute dystonia clinical review + anticholinergic reversal) + Cochrane systematic reviews (Lima — anticholinergics for acute dystonia PMID 15106194; propranolol/beta-blockers for acute akathisia PMID 15495018; benzodiazepines for acute akathisia PMID 11034738) + Poyurovsky Br J Psychiatry 2001 PMID 11581110 (mirtazapine for akathisia) + Barnes Br J Psychiatry 1989 PMID 2574607 (Barnes Akathisia Rating Scale) + ED-antiemetic-EPS evidence (Drotts Ann Emerg Med 1999 PMID 10499951; Vinson Ann Emerg Med 2001 PMID 11574794) + Caroff J Clin Psychiatry 2002 PMID 12562137 (movement-disorder spectrum) — explicitly distinguished from NMS (Strawn AJP 2007 PMID 17541055) and serotonin syndrome (Boyer NEJM 2005 PMID 15784664) — PMID:16180939
Cited evidence (PMID 10463905) — PMID:10463905
Cited evidence (PMID 15106194) — PMID:15106194
Cited evidence (PMID 15495018) — PMID:15495018
Cited evidence (PMID 11034738) — PMID:11034738