College of Psychiatric and Neurologic Pharmacists

Recognizing Movement Disorders: Reviving Old Practices

Movement disorders have many different presentations and are defined as a group of syndromes that affect the ability for one to control movement in a given muscle or muscle group. Many of the medications we use to treat psychiatric illness (antipsychotics, lithium, and valproic acid) have the potential to cause movement disorders, often referred to as extrapyramidal side effects, though predictability is lacking. Antipsychotic-induced dopamine blockade can lead to acute dystonia, akathisia, and Parkinsonism, all of which are generally reversible if treatment is discontinued. A neuroleptic-induced movement disorder that may be irreversible is tardive dyskinesia. Both lithium and valproic acid may cause tremor, the presentation of which will be explored in this issue of the Mental Health Clinician. Less often, our antidepressants may induce movement disorders similar to those caused by antipsychotics. In 2009, the U.S. Food and Drug Association placed a black box warning on the medication metoclopramide, a gastrointestinal motility agent that has some dopamine blockade effects, warning of its risk of causing tardive dyskinesia. This prompted a slew of lawsuits against manufacturers of this medication and the doctors who prescribed it without informing or monitoring their patients for this known side effect. Read the full editorial.