Expected clinical benefits of paliperidone extended-release formulation when compared with risperidone immediate-release.

The development of paliperidone extended release (ER) may represent a new strategy to improve the pharmacological treatment of schizophrenia. The drug maintains the atypical antipsychotic profile of its parent compound risperidone, but it is associated with an innovative delivery system (OROS technology) that offers the possibility to obtain smooth drug plasma levels using an oral antipsychotic. Clinical trials confirmed that paliperidone ER is efficacious in the management of schizophrenia and well tolerated, however no direct clinical comparisons between paliperidone ER and immediate-release formulations of risperidone have been conducted to date. The present study evaluates possible differences between paliperidone ER and immediate-release formulations of risperidone due to structural/molecular and delivery system diversities, providing an estimation of their significance in the context of clinical results. A search of Medline and EMBASE was performed using the keywords 'Risperidone', 'Paliperidone' and 'OROS technology'. The analysis suggests that the chemical structure and pharmacokinetic profile of paliperidone ER might provide clinical benefits in terms of efficacy, tolerability and more consistent drug response among patients, when compared with the parent compound risperidone in its immediate release formulations. The relevance of these differences is discussed, taking into account several clinical aspects involved in the drug therapy of schizophrenia.