Patients on antipsychotics need to be regularly monitored for signs of tardive dyskinesia, a medication-induced movement disorder diagnosed when the involuntary movements persist for at least a month after stopping treatment.
While tardive dyskinesia is most often caused by sustained exposure to antipsychotics, any drug that significantly blocks dopamine receptors can be a culprit, said Demian Rose, MD, PhD, of the University of California San Francisco Weill Institute for Neurosciences.
"Clinicians should be diligent about using prescribing practices that minimize the risk of tardive dyskinesia development and also monitoring for tardive dyskinesia" to detect any abnormal movements early, Meghan Musselman, MD, of the Lewis Katz School of Medicine at Temple University in Philadelphia, told 鶹ý.
"No currently available antipsychotic medication is completely without risk," she said.
The yearly incidence of tardive dyskinesia in the U.S. is around 4-8% in adults treated with a first-generation antipsychotic. This is about three times higher than the annual risk with second-generation antipsychotics, according to the 's (APA) guide on tardive dyskinesia for patients with schizophrenia.
Assessing the Patient
Screening for abnormal involuntary movements with a structured instrument should be conducted every 6 months for high-risk patients, at least every 12 months for other patients, or if a new movement or change in movement is detected at any visit, the APA states.
Symptoms of tardive dyskinesia can include involuntary facial and extremity movements lasting a few weeks: tics, grimacing, lip smacking, rapid eye blinking, chewing, and cheek puffing. Other symptoms may include repetitive finger movements, a duck-like walk, pelvis rocking, and akathisia.
Less often, symptoms can also involve the pharyngeal, diaphragm, or trunk muscles. While rare, involvement of the diaphragm can be life-threatening, said Joshua Kantrowitz, MD, of the Columbia University Department of Psychiatry and New York State Psychiatric Institute, both in New York City.
"Adults generally present on a clinical exam," he told 鶹ý. "A lot depends on how significant the symptoms are. Subtle cases are harder to diagnose, and most cases are subtle."
Children on antipsychotic medications should be regularly screened for tardive dyskinesia, Musselman pointed out.
Common assessment tools include the , the , and the .
"When using scales such as the AIMS or the DISCUS, it should be noted that there is no specific score threshold that suggests a need [for] intervention, although ranges of scores are noted to correspond with mild, moderate, and severe symptoms," APA's guideline states.
How the condition impacts quality of life depends on the severity, Kantrowitz told 鶹ý. "More-than-moderate cases can be disfiguring and create stigma."
Developed in 2022, the can help measure the condition's affect on patients' daily functioning.
Tardive dyskinesia can progress to interfere with almost all activities of daily living like getting dressed, eating, and drinking, added Rose. "In some cases, it can require a feeding tube."
First Steps of Management
If despite best prevention efforts a patient on an antipsychotic develops the hallmark uncontrolled movements of tardive dyskinesia, stopping the is the best first step when possible.
Symptoms continue to worsen if patients remain on the antipsychotic that caused it, said Kantrowitz, but abrupt discontinuation can worsen tardive dyskinesia symptoms too.
"A slow taper is the optimal way," Rose told 鶹ý. "Only 10-30% [of cases] fully resolve, most of them being in cases where the offending agent was removed."
"For those who can't tolerate discontinuation due to severe [psychiatric] symptoms, the minimum dose possible should be sought," said Rose.
Often patients aren't able to go off their treatment "cold turkey" because of the risk of exacerbating their underlying psychiatric illness, said Musselman.
"More often than simply discontinuing the offending agent, clinicians opt to switch the offending agent to an alternative antipsychotic medication that carries a lower risk of tardive dyskinesia," said Musselman. "This is particularly worth considering if the patient is prescribed a first-generation antipsychotic medication, such as haloperidol. First-generation antipsychotics typically carry a higher risk of tardive dyskinesia as compared to second-generation antipsychotic medications, including quetiapine and clozapine."
But prior to making any medication changes, clinicians must carefully weigh the benefits with the risks -- like destabilizing a patient -- and discuss options with the patient.
"In coming to a decision on treatment, the clinician and patient should consider together the impact of tardive dyskinesia on the patient's quality of life and functioning along with the risks, benefits, and potential side effects of a potential medication change," Musselman noted. "It is possible, particularly with longstanding tardive dyskinesia, that even with a change in the antipsychotic medication, that improvement in tardive dyskinesia symptoms can take months to years to improve and, at times, may not appear to improve at all."