Long-lasting extrapyramidal symptoms after multiple injections of paliperidone palmitate to treat schizophrenia

Purpose: Antipsychotic drug treatment can potentially lead to adverse events such as extrapyramidal symptoms (EPSs). If these events persist, they lower patient quality of life. The purpose of this report is to present our experience with such a case, as an example to encourage further study. Patients and methods: The patient was a 64-year-old male who had been diagnosed with schizophrenia that had been treated with oral antipsychotics for over 40 years. Due to lack of compliance, he was treated with the long-acting injectable antipsychotic, paliperidone palmitate, but developed persistent EPSs after 6 months. He was subsequently treated and monitored in our inpatient facility. Results: Antipsychotic treatment was stopped. After 6 weeks, the patient’s psychosis had worsened, but his EPSs remained unchanged. Levodopa treatment was then started (up to 400 mg/d), which improved his EPSs, so he was restarted on oral antipsychotic therapy (arip-iprazole, 6–18 mg/d). His psychotic symptoms improved over 2 months. The improvements in both psychosis and EPSs remained stable. Dopamine transporter scans revealed moderate dopamine transporter loss in the striatum, and computed tomography revealed no sign of brain abnormalities, suggesting that the patient was susceptible to dopamine reductions. Conclusion: Paliperidone palmitate can induce EPSs, even if injected only a few times. Although the characteristics of the drug are potential causes, the patient’s predisposition to dopamine perturbations can also influence the outcome. Therefore, adequate awareness is required before injection.