Medication-Induced Movement Disorders 

Medication-Induced Movement Disorders 

Medication-Induced Movement Disorders 

Medication-induced movement disorders are included in Section II because of their frequent importance in 1) the management by medication of mental disorders or other medical conditions and 2) the differential diagnosis of mental disorders (e.g., anxiety disorder versus neuroleptic-induced akathisia; malignant catatonia versus neuroleptic malignant syndrome). Although these movement disorders are labeled “medication induced,” it is often difficult to establish the causal relationship between medication exposure and the development of the movement disorder, especially because some of these movement disorders also occur in the absence of medication exposure. The conditions and problems listed in this chapter are not mental disorders.

The term neuroleptic is becoming outdated because it highlights the propensity of antipsychotic medications to cause abnormal movements, and it is being replaced with the term antipsychotic in many contexts. Nevertheless, the term neuroleptic remains appropriate in this context. Although newer antipsychotic medications may be less likely to cause some medication-induced movement disorders, those disorders still occur. Neuroleptic medications include so-called conventional, “typical,” or first-generation antipsychotic agents (e.g., chlorpromazine, haloperidol, fluphenazine); “atypical” or second-generation antipsychotic agents (e.g., clozapine, risperidone, olanzapine, quetiapine); certain dopamine receptor–blocking drugs used in the treatment of symptoms such as nausea and gastroparesis (e.g., prochlorperazine, promethazine, trimethobenzamide, thiethylperazine, metoclopramide); and amoxapine, which is marketed as an antidepressant.