A 65-year-old woman comes to the office due to involuntary facial and mouth movements. The patient first noticed the condition 6 months ago with protruding and twisting movements of the tongue and puckering movements of the lips; the movements have worsened since then. She has also experienced foot-tapping movements and an uncontrollable twisting of her neck to the right side. The patient has type 2 diabetes mellitus and chronic gastroparesis. She also has a long history of bipolar disorder that has been stable over the past year on a combination of lithium and quetiapine. Other medications include metformin and metoclopramide. She has no family history of a movement disorder or any neurologic disease.
Temperature is 37.5 C (99.5 F), blood pressure is 138/76 mm Hg, and pulse rate is 84/min. Occasional tongue protrusion, facial grimacing, cervical torticollis, slow gait, and reduced arm swing are noted.
Which of the following is the most appropriate next step in management of this patient?

Question

A 65-year-old woman comes to the office due to involuntary facial and mouth movements.  The patient first noticed the condition 6 months ago with protruding and twisting movements of the tongue and puckering movements of the lips; the movements have worsened since then.  She has also experienced foot-tapping movements and an uncontrollable twisting of her neck to the right side.  The patient has type 2 diabetes mellitus and chronic gastroparesis.  She also has a long history of bipolar disorder that has been stable over the past year on a combination of lithium and quetiapine.  Other medications include metformin and metoclopramide.  She has no family history of a movement disorder or any neurologic disease.
Temperature is 37.5 C (99.5 F), blood pressure is 138/76 mm Hg, and pulse rate is 84/min.  Occasional tongue protrusion, facial grimacing, cervical torticollis, slow gait, and reduced arm swing are noted.
Which of the following is the most appropriate next step in management of this patient?

Quizplus · Accepted Answer

11ec193a_98c4_e211_853d_e7bba43655a2_MD0002_00 This patient's lip puckering, tongue protrusion, foot tapping, and torticollis are consistent with tardive dyskinesia (TD), an involuntary movement disorder due to prolonged exposure to dopamine receptor-blocking medications (eg, antipsychotics, metoclopramide). The most appropriate treatment of medication-induced TD is discontinuation of the causative dopamine blocker agent. The antiemetic and prokinetic agent metoclopramide has a strong correlation with the occurrence of TD; risk factors include >12-week duration of treatment, older age, female sex, and history of diabetes mellitus. For patients taking antipsychotics who develop TD but still require treatment for psychosis, switching to a second-generation antipsychotic (SGA) (eg, clozapine, quetiapine) is recommended as SGAs are associated with a lower risk for TD compared to first-generation drugs. Another treatment option, recently approved by the FDA, is valbenazine, a vesicular monoamine transporter 2 inhibitor that modulates presynaptic dopamine release. (Choice A) Anticholinergic drugs such as benztropine are usually ineffective for TD and can exacerbate involuntary movements once they emerge. Benztropine is most commonly used to treat acute dystonia and parkinsonism. (Choice B) This patient's reduced arm swing and slow gait are suggestive of drug-induced parkinsonism, another extrapyramidal symptom associated with dopamine-blocking drugs that is best treated by discontinuing the offending drug. Carbidopa-levodopa can worsen dyskinetic movements and should be avoided in this patient. (Choice C) Lithium can induce tremors but would not explain this patient's lip puckering, tongue protrusion, and foot tapping, which are typical movements in TD. (Choice E) This patient is already taking an SGA (ie, quetiapine) associated with a negligible risk of TD. Among SGAs, risperidone is associated with comparatively greater dopamine antagonism and should be avoided in this patient. Educational objective: Tardive dyskinesia (TD) is a movement disorder due to prolonged exposure to dopamine receptor blockers (eg, antipsychotics, metoclopramide). Metoclopramide should be discontinued if TD develops. In cases of antipsychotic-induced TD when discontinuation is not feasible, options include switching to a second-generation antipsychotic or adding valbenazine. __________ References: Medication-induced tardive dyskinesia: a review and update. (http://www.ncbi.nlm.nih.gov/pubmed/28638290) Valbenazine for tardive dyskinesia. (http://www.ncbi.nlm.nih.gov/pubmed/28742396)

A 65-Year-Old Woman Comes to the Office Due to Involuntary