Paliperidone for the treatment of schizophrenia and schizoaffective disorders - a drug safety evaluation.

INTRODUCTION: Paliperidone, the major active metabolite of risperidone, is a second-generation antipsychotic that has been developed as an extended-release (ER) oral formulation and a long-acting injectable paliperidone palmitate (PP) formulation. Paliperidone has demonstrated efficacy in the reduction of acute schizophrenia symptoms and clinical benefits were maintained also in the long-term treatments. Paliperidone ER and PP are generally well tolerated with a predictable adverse event profile. Areas covered: Data from studies evaluating safety and tolerability in the acute and maintenance treatment of schizophrenia with paliperidone are reviewed. The reported treatment-emergent adverse events of these formulations are discussed. Expert opinion: In the treatment of schizophrenia and schizoaffective disorders the safety profile has a central role because it can enhance patient compliance. In fact treatment-emergent adverse events are one of the main causes of discontinuation in these patients. In particular the main limitation in the administration of paliperidone could be represented by the onset of hyperprolactinemia (especially in women) and of mild parkinsonism. Paliperidone has a high impact on current long-term drug strategies, especially given the new 3 month long-acting injectable formulation of PP.