Risperidone and haloperidol go head to head

For the first time, the long term efficacy of risperidone in the treatment of autism disorder (AD) has been compared with haloperidol. An open label maintenance study involving 28 children and adolescents found that risperidone was superior because it was associated with fewer side effects and a more significant improvement in symptoms such as altered sensory-motor behaviours, affectual reactions and language functions.

A recent comparison study has shown that the autism drug risperidone is superior to haloperidol in terms of its safety, efficacy and tolerability. The study, published in the European Journal of Child and Adolescent Psychiatry, is the first randomised, double-blind, controlled comparison of the two drugs. Previous studies had already shown that risperidone was a safe and effective treatment for children and adolescents with AD. Since there is currently no cure for AD, treatment is used to reduce symptoms, which include impaired social interaction, communication delays and repetitive behaviours and interests. Risperidone is an atypical antipsychotic, whereas haloperidol is a common classical psychotropic drug.

The first phase of the study lasted 12 weeks and involved thirty patients between the ages of 8 and 18 who were randomised to receive either risperidone or haloperidol. In the second phase, the open label maintenance study began and assessments were made at the intervals of 12, 16, 20 and 24 weeks. Twenty patients remained in the study, and they received neurological and physical examinations.

Various assessment measures were used to rate the participants’ behaviour. These included the Clinical Global Impression Scales-Improvement (CGII), the Ritvo-Freeman Real Life Rating Scale (RFRLRS), the Aberrant Behaviour Checklist (ABC) and the Turgay DSM-IV Pervasive Developmental Disorder Rating Scale (TPDDRS). These tools are used to assess sensory-motor behaviours, social relatedness, affectual reactions and language function.

To assess the safety of the drugs, researchers used the Extrapyramidal Symptoms Rating Scale (ESRS), which consists of a questionnaire about parkinsonian symptoms and an examination by a physician. The UKU Side-Effect Rating Scale was completed by the participants’ parents, who were asked to rate the frequency and severity of psychic, neurological and autonomic side effects. The study found that there was a statistically significant increase in weight gain for participants in the haloperidol group. Those who received haloperidol also had increased serum prolactin levels at the completion of the study.

Analysis of the data showed that participants who received risperidone had greater improvement on the CGI scale. There was a statistically significant improvement in scores on the language subscale of the RF-RLRS, but no change for those who received haloperidol. Scores for the risperidone group also improved on the ABC scale, which measures irritability, social withdrawal, stereotypic behaviour, hyperactivity and inappropriate speech. Overall, the authors found that risperidone was effective for improving scores on the subscale sensory motor behaviours for three different assessments.

The results showed conclusively that risperidone is a safer and more effective long term maintenance treatment for AD in children and adolescents. Risperidone is well tolerated and leads to a more significant improvement in language, sensory motor activities and behaviour. The study has important clinical implications, because risperidone has been shown to be superior, and should be more widely used and studied.

Reference:

Gencer O, Emiroglu F, Miral S, Baykara B, Baykara A, Dirik E. Comparison of long-term efficacy and safety of risperidone and haloperidol in children and adolescents with autistic disorder. Eur Child Adolesc Psychiatry. 2007.