Rare but Treatment-emergent Extrapyramidal Symptoms-related AdverseEvents after Administration of Long-acting Injectable PaliperidonePalmitate

Paliperidone palmitate, the long-acting injectable form of paliperidone (PLAI), is approved for once-monthly intramuscular injection [1]. Several studies suggest that the loading dose regimen for PLAI does not lead to higher rates of extrapyramidal symptoms (EPS)related treatment-emergent adverse events (TEAEs) than the oral formulation [2]. However, reports of post-injection delirium/sedation syndrome (PDSS) by olanzapine LAI raise safety issues of LAI. We report a case, which demonstrates that EPS-related TEAEs can be quite refractory to a number of pharmacological interventions and persist for more than 3 months following PLAI administration.