Dystonic Reactions


Our job can be deeply satisfying. When you are able to relieve a patient’s pain or able to help detect impending disaster and avoid it, you feel like a superhero. Sometimes something as simple a fixing a Nursemaid’s Elbow will make your day! On the other hand, however, if you give a patient a medicine and the condition worsens you can feel like a fraud. Unfortunately, medication-induced dystonic reactions do occur even when you are striving to “first do no harm.”

Extrapyramidal Syndromes

  • Parkinsonism
    • Tremor, rigidity, mask-like facial expression, and/or bradykinesia
  • Akathisia
    • Restlessness and an internal feeling of unease
  • Dystonia
    • Abnormal tonic muscle contractions
    • Can include dyskinesias = clonic muscular contractions

Dystonic Reactions

  • Dystonia = movement disorder of sustained involuntary muscle contractions.
    • May present as twisting, abnormal postures or the neck, jaw, tongue or torso.
    • May also lead to eye deviation, dysphagia, dysarthria, or even dyspnea.
    • Buccolingual dystonia is the most common form. [Hooker, 1988]
      • Consists of dysarthria, mutism, trismus, tongue protruding or retracting, facial grimacing / distortions.
    • Torticollic dystonia is the 2nd most common form.
  • Mechanism is unclear, although thought to be due to an imbalance between cholinergic and dopaminergic stimulation.
    • Dopamine antagonists (ex, antipsychotics, antiemetics, and GI motility agents) often associated with dystonic reactions. [Derinoz, 2013]
    • Anticholinergic agents (ex, diphenhydramine) often used to treat it.
  • Does not indicate an overdose.
    • One study found 70% of dystonic reactions occurred within therapeutic doses. [Derinoz, 2013]
  • Consider over-the-counter medications (~18% in Derinoz’s study were due to OTC meds).


Common Offending Agents in the Ped ED

  • Antiemetics (ex, metoclopramide, promethazine)
    • Ondansetron has practically revolutionized management in the Peds ED of vomiting, because it is less likely to cause dystonic reactions.
    • While there is less risk of dysonia with ondansetron, it still can occur. [Sprung, 2003]
  • Antipsychotics (ex, Haloperidol, Risperidone, Chlorpromazine)
  • Antiepileptics (ex, Pheytoin, Carbamazepine)
  • Sedatives (ex, Benzodiazepines) [Hooker, 1988]
    • Paradoxical Reactions can also be seen with Benzodiazepines.
    • The patient becomes agitated and delirious.
    • Flumazenil administration has been reported to be helpful to alleviate these symptoms. [Jackson, 2015]


Diphenhydramine to the Rescue

  • H1-antagonism is effective in relief of dystonic symptoms.
  • Can be given orally, intravenously, or intramuscularly.
  • Interestingly… diphenhydramine can also CAUSE dystonic reactions.


Other Entities to Consider

  • Deep space neck abscess (Retropharyngeal abscess)
  • Tetanus
  • Seizure
  • Calcium deficiency
  • Drug intoxication
  • Meningitis / Encephalitis
  • Stroke
  • Conversion disorder



Jackson BF1, Beck LA2, Losek JD1. Successful flumazenil reversal of paradoxical reaction to midazolam in a child. J Emerg Med. 2015 Mar;48(3):e67-72. PMID: 25497845. [PubMed] [Read by QxMD]

Derinoz O1, Caglar AA. Drug-induced movement disorders in children at paediatric emergency department: ‘dystonia’. Emerg Med J. 2013 Feb;30(2):130-3. PMID: 22398848. [PubMed] [Read by QxMD]

Sprung J1, Choudhry FM, Hall BA. Extrapyramidal reactions to ondansetron: cross-reactivity between ondansetron and prochlorperazine? Anesth Analg. 2003 May;96(5):1374-6, table of contents. PMID: 12707136. [PubMed] [Read by QxMD]

Sean M. Fox
Sean M. Fox

I enjoy taking care of patients and I finding it endlessly rewarding to help train others to do the same. I trained at the Combined Emergency Medicine and Pediatrics residency program at University of Maryland, where I had the tremendous fortune of learning from world renowned educators and clinicians. Now I have the unbelievable honor of working with an unbelievably gifted group of practitioners at Carolinas Medical Center. I strive every day to inspire my residents as much as they inspire me.

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