Risperidone Beyond Psychoses

Yoon, Doh Joon; Bahn, Geon Ho

Abstract

The authors have compiled the available references on the use of risperidone in 'non-psychotic conditions', not including schizophrenia and bipolar disorders. In addition, information was gathered on the mechanism of action of risperidone in this diverse disorders. Atypical antipsychotics are known to have fewer adverse effects seen with typical antipsychotics, such as tardive dyskinesia (TD), neuroleptic malignant syndrome (NMS), and cognitive disturbances, and they possess a 'broad range of therapeutic efficacy.' The broad psychotropic effects, apart from the antipsychotic action, of risperidone are attributed to their particular pharmacological properties, which differ greatly from those of typical antipsychotics. Risperidone has a greater affinity for the dopamine D2 receptor than for the D1 receptor, but its D2/5-HT2 affinity ratio is low. This fixed D2/5-HT2 ratio may bring about significantly different clinical effects depending on the dosage. The dose-dependent pharmacologic properties of risperidone, in the form of the effects of blocking the 5-HT2 receptors, which are observed at smaller doses, and the effects of D2 blockade, which are manifested progressively with increasing dosage, may be the basis of the efficacy of risperidones in non-psychotic conditions at smaller doses than in psychoses. The authors have also ascertained that risperidone may be of efficacy in the treatment of non-psychotic conditions other than the major psychoses. The authors consider the different dosages depending on the diagnoses to be reflective of differences in the etiopathophysiology between the conditions. In addition, the authors have noted that risperidone, at small doses, shows efficacy in the treatment of a wide variety of disorders other than psychotic disorders, including obsessive symptoms, anxiety. This also demonstrates the greater range of therapeutic efficacy of risperidone other than typical antipsychotics. Despite the fact that risperidone possesses such various therapeutic actions, the first-line drugs in the treatment of non-psychotic conditions are and should be non-antipsychotic psychotropics;risperidone is still an antipsychotic drug, with all the entailing characteristics, and it is not completely free of the side effects common in typical antipsychotics, such as EPS. Wisdom is called for in the appropriate application of risperidone in the treatment regimen of suitable patients following treatment with other non-antipsychotic psychotropics. It seem to review all non-psychotic psychiatric disorders via the clinical applications of risperidone. Through expansion of the indications for risperidone, further insight will be gained on its previously unknown psychotropic effects and the etiopathophysiology of the indicated conditions.