3 questions with a pharmacy faculty member on Tardive Dyskinesia
Medscape, a medical website owned by WebMD, recently visited UMKC to interview Nelson for a three-episode series on Tardive Dyskinesia, an area of expertise Nelson is known for worldwide. Also called TD for short, the condition is characterized by repetitive, involuntary movements that can be seen anywhere in the body but most commonly in face. It can be serious and potentially irreversible.
Why do people get Tardive Dyskinesia?
Symptoms of TD are typically observed in patients who have received medications that antagonize the dopamine receptors in the brain, in particular long-term exposure to antipsychotics and metoclopramide. The “older” first generation antipsychotics, like haloperidol, have a higher risk than newer second-generation antipsychotics.
Anyone taking a dopamine receptor antagonist is at risk of developing TD. Longer duration of exposure to an antipsychotic, and at higher doses, increases the risk. It is well established that antipsychotic exposure and older age is a risk factor for TD. Other less-established risk factors include female sex, African American ethnicity, preexisting mood disorder, cognitive disturbance or substance-use disorder, early susceptibility to other neurologic side effects associated with antipsychotics and presence of diabetes and HIV.
What are its symptoms?
Common involuntary movements are tongue protrusion, lip puckering, chewing motion of mouth and grimacing. Abnormal movements can also be seen in the truncal region, legs, feet and hands, but are less common. All of these movements can vary in severity from mild to severe. TD can be stigmatizing to the individual and can significantly interfere with daily functioning.
How do you treat it?
Prevention is the key to managing TD. Prescribe antipsychotics based on treatment guidelines and do not use off-label for conditions like insomnia or anxiety. Use the lowest effective dose of the antipsychotics to treat chronic conditions such as schizophrenia. Perform assessments for TD on a scheduled basis for all patients taking antipsychotics to aid in early identification.
Treatment of TD was an unmet need until 2017 and no drug was FDA approved for treating TD until last year. Prior to 2017, treatment of TD included Vitamin E, tetrabenazine, ginkgo biloba and clonazepam although none of these drugs were well studied for TD and showed minimal benefit. Two new drugs, valbenazine and deutetrabenazine, were the first drugs to be FDA approved for the indication of TD.
My research site was involved in the clinical trials for deutetrabenazine.