Drug-induced parkinsonism: A case report.

Drug-induced parkinsonism is defined as the appearance of parkinsonism on treatment with pharmaceutical agents. Symptoms typically manifest within a few days, and 90% of cases emerge within 3 months. The patient was a 68-year-old white man with a past psychiatric history significant for bipolar I versus cyclothymic disorder. The patient presented with pressured speech, flight of ideas, distractibility, delusions, and disorganized thinking. He was started on risperidone and, due to a subclinical response, was cross-tapered from risperidone to olanzapine, and divalproex was started. The patient was then given paliperidone 234 mg long-acting injection (LAI) and a second loading dose of 156 mg 1 week later. The patient's cognitive and functional status subsequently declined, all neuroleptics were discontinued, and he was diagnosed with drug-induced parkinsonism. After a complicated hospital course the patient died approximately 5 months after the administration of paliperidone LAI. Although there are several confounding factors, due to the temporal relationship of events it is likely that paliperidone LAI was a contributing factor for the development of severe parkinsonism. Practitioners should be cognizant of the potential long-term consequences of paliperidone LAI.