Rivastigmine-induced dystonia

A case of acute dystonia related to rivastigmine use is reported.

A 61-year-old Caucasian woman who had suffered from bipolar II disorder with rapid cycling for over 30 years was admitted to an inpatient psychiatry unit. In addition to bipolar II disorder, the patient had been previously diagnosed with early-stage Alzheimer's disease, posttraumatic stress disorder, and various anxiety disorders. During the current hospitalization, she was taking clonazepam, dextroamphetamine, lamotrigine, lansoprazole, levothyroxine, memantine, quetiapine, risperidone, rivastigmine, tranylcypromine, trazodone, and zolpidem. Soon after hospital admission, she began to complain of a tightening in her chest. A review of her records revealed similar complaints during previous hospitalizations. Rivastigmine was discontinued due to concerns of interactions with her antipsychotic regimen. Although these symptoms were previously attributed to anxiety, they appeared worse during this hospitalization. During these events she would be witnessed lying in bed in a supine position with her head canted posteriorly. Benztropine was given to help determine if she was having a dystonic reaction. Within 30 minutes, her chest discomfort began to resolve, and her symptoms resolved completely over the next 48 hours. Three days later, rivastigmine was restarted by the attending psychiatrist because of concerns about the patient's memory, and the dystonia-like symptoms returned within 2 hours of her morning dose. Rivastigmine was discontinued, and benztropine was given and then discontinued, with no return of symptoms for the remainder of her two-week hospitalization.

A patient with bipolar II disorder and mild-to-moderate Alzheimer's disease developed dystonia, possibly caused by rivastigmine. However, the patient was taking various other medications that could have lowered the threshold for extrapyramidal syndromes.