Comparison of long-term efficacy and safety of risperidone and haloperidol in children and adolescents with autistic disorder - An open label maintenance study

Background The aim of the study was to investigate safety, efficacy and tolerability of risperidone in comparison with haloperidol in the long-term treatment of autistic disorder. Methods This was an open-label continuation study of the randomized, double-blind, controlled trial of risperidone and haloperidol study for 12 week in autistic children and adolescents. A total of 28 subjects between 8 and 18 ages with autistic disorder were enrolled to the open label phase of the study. Behavioral rating scales (Clinical Global Impression Scale [CGI-I], Ritvo-Freeman Real Life Rating Scale [RF-RLRS]), Aberrant Behavior Checklist [ABC], Turgay DSM-IV Pervasive Developmental Disorder Rating Scale [TPDDRS]) and safety assessment scales (Extrapyramidal Symptoms Rating Scale [ESRS], UKU-Side Effect Rating Scale) were performed at 12, 16, 20 and 24 weeks, following the 12 week double-blind phase. Risperidone and haloperidol treatments were applied with a once daily dosage regimen as 0.01-0.08 mg/kg/day. Results Risperidone led to a significant greater reduction on CGI scale. There was significant improvement on RF-RLRS sensory motor and language subscale and ABC scores in risperidone group. Weight gain was observed more frequently in the haloperidol group at week 24. Conclusions These results demonstrate that risperidone is more efficacious and well tolerated than haloperidol in the long-term maintenance treatment of autistic disorder