Tardive dyskinesia (TD) is a movement disorder that starts after the use of a dopamine receptor blocking medication for at least a few months (or a shorter duration in older patients). These medications include most antipsychotic medications and metoclopramide. In TD, the movement disorder can consist of chorea, athetosis, akathisia, or dystonia. The severity of TD is assessed using the Abnormal Involuntary Movement Scale (AIMS). TD is a diagnosis of exclusion. Other neurologic causes of the movement disorder should be excluded before a diagnosis of TD is made. When a patient develops TD while taking a dopamine receptor blocker, the first intervention is to taper and discontinue the offending medication. TD can transiently get worse while tapering. Tapering should be done with close monitoring, since it can worsen symptoms of psychosis or depression. If a patient continues to require antipsychotic medication, the medication used should be a second generation antipsychotic at the lowest effective dosage. There is little evidence to support any particular second-generation medication, with the exception of quetiapine and clozapine. Quetiapine has a low level of dopamine blockade, and sometimes allows TD to improve. Clozapine has no liability for movement disorders or TD, and sometimes allows TD to improve. For information on clozapine, visit the SMI Adviser Clozapine Center of Excellence.
Every antipsychotic medication can cause side effects, and this guides the treatment plan. During antipsychotic medication tapering or change, new dyskinesias may occur. These often improve and do not necessarily require treatment. At this point, the need for further treatment of TD should be assessed; symptoms can sometimes be mild and not result in disability or be bothersome. If the TD is clinically significant, pharmacologic treatment should be considered. While many medications have been tried, when studied, only a few have improved TD. Treatment guidelines recommend that patients who have moderate to severe or disabling tardive dyskinesia be treated with a reversible inhibitor of the vesicular monoamine transporter-2 (VMAT2). Three VMAT2 inhibitors are available in the U.S.: deutetrabenazine, valbenazine and tetrabenazine. Deutetrabenazine and valbenazine have been found safe and effective in clinical trials and are approved by the FDA to treat TD. Other treatments that have been used successfully in some cases include benzodiazepines for mild TD; and botulinum toxin injections or anticholinergic medications for tardive dystonia. Deep brain stimulation in the globus pallidus has been used successfully in some severe cases.