Drug-induced dystonia is reversible and presents as acute, disorganized contraction of muscle groups. It generally occurs soon after the administration of antipsychotic, antiemetic, antidepressant and antiepileptic drugs, however other drugs have also been known to induce the condition [1] [2] [3]. It is thought that this is due to the drugs' inhibitory effect on the dopamine system in the central nervous system. It appears commonly when the drug is initiated or when the dose of the drug is increased. Higher doses and greater potency of causative drugs, particularly neuroleptic drugs are associated with as higher incidence [4]. In addition, first-generation antipsychotics, such as haloperidol, have been implicated more than second-generation antipsychotics. Symptoms appear within hours of administration of the initial dose of antipsychotics, and up to one month after antidepressants are started [5]. Younger patients, concurrent substance use, particularly alcohol and cocaine, family history of dystonia are associated with a higher risk of the condition [6].

Drug-induced dystonia is seldom a source of fatalities [7]. It does, however, cause significant patient distress, and is frequently misdiagnosed [8]. It usually involves the muscles of the face and neck but is not restricted to these. Episodes are characterized by sustained uncontrollable motions that may or may not be heralded by voluntary movement. Facially, the muscles of the eye can be affected, causing what may appear to be excessive blinking. The muscles may also constantly contract, forcing the gaze to remain in a certain direction resulting in an oculogyric crisis. Involvement of the facial muscles causes twitching of the lips, dysarthria, dysphonia and buccolingual crisis; if laryngeal or pharyngeal musculature are affected then there could be airway compromise [9] while torticollis results from sternocleidomastoid muscle involvement.

On the torso, distortion of the spine, opisthotonus, as well as a tortipelvic crisis, which involves rigidity of the pelvic and abdominal musculature, can occur. Any muscle group can be affected, and it can eventually become painful with the formation of contractures [10]. Moreover, a serious and debilitating form of the disorder called tardive dystonia may follow.

• Malingering

  […] room doctors and neurologists, because of the high probability of misdiagnosis, due to the presence of several mimickers including partial seizures, meningitis, localized tetanus, serum electrolyte level abnormalities, strychnine poisoning, angioedema, malingering [ncbi.nlm.nih.gov]

  These tactile maneuvers may lead physicians to the erroneous diagnosis of malingering or hysteria. [pocketdentistry.com]

• Dentist

  Although the dentist will not be doing this examination, it is necessary to identify whether a patient has had a correct assessment before participating in the management of the patient. [pocketdentistry.com]

• Gingival Overgrowth

  […] drug-induced constipation drug-induced cystitis drug-induced disease Drug-induced dystonia Drug-Induced Extra-Pyramidal Symptoms Scale drug-induced gingival hyperplasia drug-induced gingival hyperplasia drug-induced gingival hyperplasia Drug-Induced Gingival [encyclopedia2.thefreedictionary.com]

• Angioedema

  […] emergency room doctors and neurologists, because of the high probability of misdiagnosis, due to the presence of several mimickers including partial seizures, meningitis, localized tetanus, serum electrolyte level abnormalities, strychnine poisoning, angioedema [ncbi.nlm.nih.gov]

  Angioedema (Medical Encyclopedia) Drug allergies (Medical Encyclopedia) Drug-induced diarrhea (Medical Encyclopedia) Drug-induced tremor (Medical Encyclopedia) Taking multiple medicines safely (Medical Encyclopedia) [ Read More ] Dystonia Dystonia is [icdlist.com]

  Eighteen months before she had presented a similar episode interpreted as tongue angioedema, spontaneously resolved. She had no history of recent head or neck injury, substance abuse, or infection. [journals.lww.com]

• Dermatitis

  ) blood disorders ( D56 - D76 ) contact dermatitis ( L23 - L25 ) dermatitis due to substances taken internally ( L27.- ) nephropathy ( N14.0- N14.2 ) Includes adverse effect of correct substance properly administered poisoning by overdose of substance [icd10data.com]

• Dystonia

  The highest frequencies of dystonia occurred among recipients of haloperidol and the long-acting injectable fluphenazines. For all patients at risk, dystonia was more common in men and in younger patients. [ncbi.nlm.nih.gov]

  Moreover, a serious and debilitating form of the disorder called tardive dystonia may follow. There are no tests tailored to diagnose drug-induced dystonia. [symptoma.com]

  […] dyskinesia (disorder) Drug-induced dystonia Drug-induced dystonia (disorder) Drug-induced orofacial dyskinesia Drug-induced orofacial dyskinesia (disorder) Drug-induced tardive dyskinesia Drug-induced tardive dystonia Major Diagnostic Categories M.D.C [medicbind.com]

• Extrapyramidal Symptoms

  2348023076154; E-mail: [email protected] Abstract: Acute drug induced dystonias are commonly reported with antipsychotic drugs, however there have been reports of extrapyramidal symptoms following the use of 4-aminoquinolones such as chloroquine [content.iospress.com]

  Extrapyramidal symptoms after exposure to calcium channel blocker-flunarizine or cinnarizine. Jhang KM, Huang JY, Nfor ON, Tung YC, Ku WY, Lee CT, Liaw YP Sertraline induced mandibular dystonia and bruxism. [medicbind.com]

  symptoms Keyword: Tardive dyskinesia, Neuroleptic-induced movement disorders, Quetiapine, Chronic schizophrenia, Extrapyramidal symptoms pp.49-57 発行日 2004年1月15日 Published Date 2004/1/15 DOI Copyright 2004, Igaku-Shoin Ltd. [webview.isho.jp]

  Most of us learned in our professional training that neuroleptic agents cause movement disorders, or extrapyramidal symptoms (EPS).1 Neuroleptics, the older class of antipsychotic agents, which includes dopamine receptor blocking agents (DRBA), can cause [the-hospitalist.org]

  Therefore, physicians must be cautious of prescribing metoclopramide and should consider other antiemetics such as domperidone, which has less frequent extrapyramidal symptoms [ 5 ]. [ceemjournal.org]

• Vocal Tic

  This includes Bell’s palsy, essential tremor, the focal and multifocal dystonias, the dyskinesias, the motor and vocal tics, and hemifacial spasm. [pocketdentistry.com]

There are no tests tailored to diagnose drug-induced dystonia. It should be suspected and considered as a possible etiology of symptoms, based on patient history and physical findings. The condition readily responds to treatment and this may indirectly confirm the diagnosis. However, a psychiatrist consult may be required if the diagnosis is doubtful.

1. Elliott ES, Marken PA, Ruehter VL. Clozapine-associated extrapyramidal reaction. Ann Pharmacother. 2000;34(5):615-618.
2. Jhee SS, Zarotsky V, Mohaupt SM, Yones CL, Sims SJ. Delayed onset of oculogyric crisis and torticollis with intramuscular haloperidol. Ann Pharmacother. 2003;37(10):1434-1437.
3. Tekin U, Soyata AZ, Oflaz S. Acute focal dystonic reaction after acute methylphenidate treatment in an adolescent patient. J Clin Psychopharmacol. 2015;35(2):209-211.
4. van Harten PN, Hoek HW, Kahn RS. Acute dystonia induced by drug treatment. BMJ. 1999;319(7210):623–626.
5. Hawthorne JM, Caley CF. Extrapyramidal Reactions Associated with Serotonergic Antidepressants. Ann Pharmacother. 2015;49(10):1136-1152.
6. Zakariaei Z, Taslimi S, Tabatabaiefar MA, Arghand Dargahi M. Bilateral dislocation of temporomandibular joint induced by haloperidol following suicide attempt: a case report. Acta Med Iran. 2012;50(3):213-215.
7. Freudenreich O. Atypical laryngeal dystonia caused by an antiemetic. Am Fam Physician. 2004;69(7):1623.
8. Dingli K, Morgan R, Leen C. Tetanus versus acute dystonic reaction caused by metoclopramide. BMJ. 2007;334(7599):899–900.
9. Munhoz RP, Moscovich M, Araujo PD, Teive HA. Movement disorders emergencies: a review. Arq Neuropsiquiatr. 2012;70(6):453–461.
10. Dystonias information page. National Institute of Neurological Disorders and Stroke. Accessed March 26,2017.