An Open-Label Trial of Risperidone and Fluoxetine in Children with Autistic Disorder

Article excerpt

Byline: Avinash. Desousa

Objective: Various studies have shown the effectiveness of risperidone and fluoxetine in the management of behavioral problems in autism. Aim: The purpose of this study was to compare these two drugs in the management of behavioral problems in autism. Materials and Methods: Forty children with autism were divided into 2 groups in a 16-week open trial that compared these two drugs. Parents rated the children using the Aberrant Behavior Checklist (ABC) and the Conners' Parent Rating Scale - Revised (CPRS-R). The author rated the children using the Children's Psychiatric Rating Scale and Clinical Global Impression (CGI) Scale. Results: The risperidone group showed significant improvement in areas like irritability and hyperactivity, while the fluoxetine group showed significant improvement in speech deviance, social withdrawal and stereotypy. When the two drugs were compared, fluoxetine showed greater improvement in stereotypy, while both drugs showed improvement on the general autism scale; and on anger, hyperactivity and irritability scales. Conclusions : In this open trial, both drugs were well tolerated and appeared to be beneficial in the treatment of common behavioral problems in children with autism. Further controlled and double-blind studies in larger samples are warranted.

Introduction

There are currently no treatments available that are specific for autism. Diverse pharmacological agents have been used in children with autistic disorder - few in trials and many reported in anecdotal case reports. Most treatments are aimed at reducing associated behaviors like aggression, agitation, inattention and hyperactivity. [sup][1] The pharmacotherapy of autism is focused on primary emotional and behavioral target symptoms and matching these targets with medications that are likely to be helpful. [sup][2],[3]

Risperidone is an atypical antipsychotic drug that belongs to the benzisoxazole derivative class. Its actions are mediated by antagonism of the dopamine type 2 (D2) and serotonin type 2 (5HT2) receptors. It has fewer extrapyramidal symptoms as side effects compared to typical antipsychotics, although reports of tardive dyskinesia, hepatotoxicity and weight gain exist.[sup][4],[5],[6] There are a number of reports that suggest modest efficacy of risperidone in the management of behavioral symptoms in children with autistic disorder.[sup][7],[8],[9],[10],[11]

Work specifically examining the association between serotonergic regulation and autism dates back to 1961, when a study reported elevated whole blood levels of serotonin in autistic individuals.[sup][12] Potent serotonin-transporter inhibitors are often used to address symptoms like compulsions and repetitive behavior, obsessions, anxiety, irritability and depression. These medications are useful when symptoms like insistence on routine are present and aggression in response to interruption of routines manifests as seen in autistic disorder.[sup][13],[14]

Selective serotonin reuptake inhibitors (SSRIs) in open-label investigations have been found to be useful in children with pervasive developmental disorders (PDDs). Favorable responses to nearly all drugs in this group have been noted.[sup][15],[16],[17],[18],[19],[20],[21] Common side effects associated with these drugs are decreased appetite, motor restlessness, irritability and insomnia.[sup][22] Larger number of studies and reports are present with fluoxetine than with other drugs. Due to a perceived sensitivity to these agents in those with autism, it is hypothesized that starting at a low dose and titrating slowly upward would prove superior in terms of outcome when using these drugs in autistic children.[sup][23]

To the best of our knowledge, this study is the first open trial that compares these two agents in the management of autistic disorder.

Aim of the study

The aim of the study was to compare the efficacy and safety of risperidone and fluoxetine in children and adolescents with autistic disorder/ autism. …