Parkinsonism With Intramuscular Ziprasidone

Mr. A, a 63-year-old man with history of chronic paranoid schizophrenia, was admitted to the inpatient unit to help manage his uncontrollable violent behavior. He was hypervigilant, paranoid, and actively conversing with inner voices. He refused to take oral medications, including his preadmission regimen of olanzapine, 30 mg/day, and valproic acid, 2000 mg/day. He then assaulted staff members twice, necessitating use of restraints and intramuscular haloperidol, 10 mg/day, for 3 consecutive days. A day after his last haloperidol injection, we gave him 20 mg b.i.d. of intramuscular ziprasidone. Mr. A received 20 mg on day 1, 20 mg b.i.d. on day 2, and 20 mg b.i.d., with an additional third dose of 20 mg at noon on day 3, for emergent aggression. Drooling, a flat expression, bradykinesia, a shuffling gait, and pill-rolling tremor appeared later that day. His symptom profile fit drug-induced parkinsonism. We then restricted his dose to 40 mg/day, and Mr. A’s parkinsonism symptoms subsequently resolved. However, at that dose, his aggression continued; therefore, we discontinued ziprasidone and started intramuscular olanzapine, which reduced the agitation and allowed resumption of oral medication administration.