Back To Search Results

Dystonic Reactions

Editor: Carla S. O'Day Updated: 5/1/2023 7:15:13 PM


An acute dystonic reaction is characterized by involuntary contractions of muscles of the extremities, face, neck, abdomen, pelvis, or larynx in either sustained or intermittent patterns that lead to abnormal movements or postures. The symptoms may be reversible or irreversible and can occur after taking any dopamine receptor-blocking agents. The etiology of acute dystonic reaction is thought to be due to dopaminergic-cholinergic imbalance in the basal ganglia. Reactions usually occur shortly after the initiation of an offending agent or an increased dose of a possible offending agent. Anticholinergic agents and benzodiazepines are the most commonly used agents to reverse or reduce symptoms in acute dystonic reaction. Acute dystonic reactions are often transient but can cause significant distress to the patient. Although rare, laryngeal dystonia can cause life-threatening airway obstruction.


Register For Free And Read The Full Article
Get the answers you need instantly with the StatPearls Clinical Decision Support tool. StatPearls spent the last decade developing the largest and most updated Point-of Care resource ever developed. Earn CME/CE by searching and reading articles.
  • Dropdown arrow Search engine and full access to all medical articles
  • Dropdown arrow 10 free questions in your specialty
  • Dropdown arrow Free CME/CE Activities
  • Dropdown arrow Free daily question in your email
  • Dropdown arrow Save favorite articles to your dashboard
  • Dropdown arrow Emails offering discounts

Learn more about a Subscription to StatPearls Point-of-Care


Antipsychotic and antiemetic agents are among the most commonly described causative agents of acute dystonic reactions. Other agents including anti-malarial, antidepressants, antihistamines, and anticonvulsants have also been implicated in cases of acute dystonic reaction. Antipsychotic agents with a dopamine-blocking mechanism are commonly used to treat acute psychosis, acute agitation, bipolar mania, and many other psychiatric conditions. All currently known antipsychotic medications carry a risk of causing an acute dystonic reaction. First-generation antipsychotics including haloperidol and thioridazine are associated with a higher risk of acute dystonic reaction. Second-generation antipsychotics including olanzapine, risperidone, and quetiapine are associated with a reduced risk of dystonic reaction which is postulated to be due to more rapid dissociation of the drugs from the D2 receptor sites. The antiemetic agents metoclopramide and prochlorperazine are also common agents leading to an acute dystonic reaction, even leading some practitioners to co-administer diphenhydramine.[1] Case reports demonstrate that drugs such as methylphenidate, albendazole, chloroquine, rivastigmine, and foscarnet have all been implicated in cases of acute dystonic reaction.[2][3][4]


The incidence of acute dystonic reactions, in general, is not currently known. The incidence of metoclopramide-induced extrapyramidal symptoms is estimated to be 1:500.[4] Risk factors for acute dystonic reaction are male gender, young age, previous episode of acute dystonia, or recent cocaine use.[5][6] One study revealed a 6.8% prevalence of acute dystonic reactions in adults treated with antipsychotics. [7]


The basal ganglia are a collection of subcortical nuclei through which information from the cortex is modulated and returned to the cortex to execute a coordinated movement. Acetylcholine has grossly inhibitory effects on movement, and dopamine has grossly excitatory effects on movement. Certain medications act to block dopamine receptors, leading to a potential pro-movement state. Acute dystonic reactions are postulated to be a result of an imbalance of anticholinergic and dopaminergic effects in this pathway.[8]

History and Physical

Below are descriptions of the well-defined presentations of acute dystonic reactions.[9][10][11]

  • Buccolingual Crisis - trismus, risus sardonicus, dysarthria, dysphagia, grimacing, tongue protrusion.
  • Oculogyric Crisis - spasm of the extraocular muscles, most commonly deviated upward.
  • Torticolic Crisis - abnormal asymmetric head or neck position.
  • Tortipelvic Crisis - abnormal contractions of the abdominal wall, hip, and pelvic musculature. 
  • Opisthotonic Crisis - characteristic flexion posturing with arching of the back
  • Laryngeal Dystonia - dysphonia, stridor
  • Pseudomacroglossia - patient describes the sensation of tongue swelling and protrusion. 


Evaluation of the patient with acute dystonic reaction should be performed with the same basic steps as any other acute presentation including assessment of airway, breathing, and circulation. Subtle signs such as dysphonia or complaints of throat discomfort following administration of a potential offending agent should raise suspicion of laryngeal dystonia. Definitive airway management with intubation should be considered in any patient who appears to be having difficulty protecting their airway or failing to ventilate or oxygenate. A thorough history and physical exam should be performed, looking for signs of other acute conditions including stroke and seizure. Special attention should be given to recently administered medications, and they should be reviewed for potential dopamine-blocking effects. Drug paraphernalia or the presence of, or report of, illicit substances may raise suspicion that the patient’s drugs may have been cut or spiked with an offending pharmacologic agent.[12] In cases of acute dystonic reaction, mental status and vital signs should remain normal.

Treatment / Management

Treatment of acute dystonic reaction centers around balancing the disrupted dopaminergic-cholinergic balance in the basal ganglia and discontinuation of the offending agent. The most commonly available drugs in the emergency setting for the treatment of acute dystonic reactions are diphenhydramine and benztropine. Symptoms usually improve or resolve dramatically within 10 to 30 minutes of administration of parenteral anticholinergics. The half-life of most antipsychotic agents is longer than that of most diphenhydramine or benztropine requiring re-dosing of anticholinergic medications.

Supportive measures such as oxygen or assisted ventilation should be provided immediately if indicated.

Diphenhydramine is used for its anticholinergic effect and central nervous system (CNS) penetration. Intravenous administration is preferred to intramuscular administration due to its faster onset. Typical dosing for diphenhydramine is 50 mg intravenous (IV) in adults and 1 mg/kg up to 50mg IV in pediatric patients. Once the acute dystonic reaction is treated and symptoms improve, diphenhydramine should be administered via the oral route every 6 hours for 1 to 2 days to prevent recurrence of symptoms.

Benztropine is another anticholinergic medication with significant CNS penetration. Use, however, may be limited due to availability in the emergent setting. IV and intramuscular (IM) routes are of a similar time to onset of effect.  Typical dosing of benztropine is a single dose of 1 to 2 mg IV followed by 1 to 2 mg by mouth twice a day for up to 7 days to prevent a recurrence. Benztropine use in pediatric patients for acute dystonia is considered off-label.

Second-line therapy with IV benzodiazepines may be considered for patients that fail to respond completely to anticholinergic therapy. IV or IM lorazepam at 0.05 to 0.10 mg/kg or IV diazepam at 0.1 mg/kg may be considered.

Patients who experience respiratory symptoms or required supportive oxygen should be observed for 12 to 24 hours following resolution of symptoms to monitor for recurrence.

For patients that experienced an acute dystonic reaction on antipsychotic medication, close follow-up with psychiatry should be given. If the continuation of the offending agent is necessary, the patient should be continued on an anticholinergic medication until an agent with less potential for a dystonic reaction can be initiated.

Differential Diagnosis

The following are conditions that may mimic the acute dystonic reaction: conversion disorder, tetanus, focal seizure, strychnine poisoning, hypocalcemia, anticholinergic toxicity, meningitis, neuroleptic malignant syndrome, stroke, temporomandibular joint dislocation, mandibular fracture, orbital fracture, and clonus.

Enhancing Healthcare Team Outcomes

As with any acute medical condition, close communication between patients, physicians, nurses, and other healthcare team members is essential to the early recognition and treatment of acute dystonic reactions. Nurses, pharmacists, and physicians should be familiar with the symptoms of an acute dystonic reaction and monitor patients closely for adverse reactions following the administration of medications known to cause acute dystonic reactions.

Evidence presented in this article is derived mostly from case series and expert opinion. (Level III)



Wijemanne S, Jankovic J, Evans RW. Movement Disorders From the Use of Metoclopramide and Other Antiemetics in the Treatment of Migraine. Headache. 2016 Jan:56(1):153-61. doi: 10.1111/head.12712. Epub 2015 Nov 17     [PubMed PMID: 26573884]


Incecik F, Hergüner MO, Ozcan K, Altunbaşak S. Albendazole-induced dystonic reaction: a case report. The Turkish journal of pediatrics. 2011 Nov-Dec:53(6):709-10     [PubMed PMID: 22389999]

Level 3 (low-level) evidence


Tekin U, Soyata AZ, Oflaz S. Acute focal dystonic reaction after acute methylphenidate treatment in an adolescent patient. Journal of clinical psychopharmacology. 2015 Apr:35(2):209-11. doi: 10.1097/JCP.0000000000000266. Epub     [PubMed PMID: 25607477]

Level 3 (low-level) evidence


Tianyi FL, Agbor VN, Njim T. Metoclopramide induced acute dystonic reaction: a case report. BMC research notes. 2017 Jan 7:10(1):32. doi: 10.1186/s13104-016-2342-6. Epub 2017 Jan 7     [PubMed PMID: 28061898]

Level 3 (low-level) evidence


Digby G, Jalini S, Taylor S. Medication-induced acute dystonic reaction: the challenge of diagnosing movement disorders in the intensive care unit. BMJ case reports. 2015 Sep 21:2015():. doi: 10.1136/bcr-2014-207215. Epub 2015 Sep 21     [PubMed PMID: 26392457]

Level 3 (low-level) evidence


Pinto JM, Babu K, Jenny C. Cocaine-induced dystonic reaction: an unlikely presentation of child neglect. Pediatric emergency care. 2013 Sep:29(9):1006-8. doi: 10.1097/PEC.0b013e3182a3204d. Epub     [PubMed PMID: 24201982]

Level 3 (low-level) evidence


Tural Hesapcioglu S, Ceylan MF, Kandemir G, Kasak M, Sen CP, Correll CU. Frequency and Correlates of Acute Dystonic Reactions After Antipsychotic Initiation in 441 Children and Adolescents. Journal of child and adolescent psychopharmacology. 2020 Jul:30(6):366-375. doi: 10.1089/cap.2019.0123. Epub 2020 Apr 7     [PubMed PMID: 32255662]


Sykes DA, Moore H, Stott L, Holliday N, Javitch JA, Lane JR, Charlton SJ. Extrapyramidal side effects of antipsychotics are linked to their association kinetics at dopamine D(2) receptors. Nature communications. 2017 Oct 2:8(1):763. doi: 10.1038/s41467-017-00716-z. Epub 2017 Oct 2     [PubMed PMID: 28970469]


Albanese A. How Many Dystonias? Clinical Evidence. Frontiers in neurology. 2017:8():18. doi: 10.3389/fneur.2017.00018. Epub 2017 Feb 3     [PubMed PMID: 28217105]


Barow E, Schneider SA, Bhatia KP, Ganos C. Oculogyric crises: Etiology, pathophysiology and therapeutic approaches. Parkinsonism & related disorders. 2017 Mar:36():3-9. doi: 10.1016/j.parkreldis.2016.11.012. Epub 2016 Nov 23     [PubMed PMID: 27964831]


Barach E, Dubin LM, Tomlanovich MC, Kottamasu S. Dystonia presenting as upper airway obstruction. The Journal of emergency medicine. 1989 May-Jun:7(3):237-40     [PubMed PMID: 2568376]

Level 3 (low-level) evidence


Deik A, Saunders-Pullman R, Luciano MS. Substance of abuse and movement disorders: complex interactions and comorbidities. Current drug abuse reviews. 2012 Sep:5(3):243-53     [PubMed PMID: 23030352]

Level 3 (low-level) evidence