Effectiveness and Adverse Effects of Risperidone in Children with Autism Spectrum Disorder in a Naturalistic Clinical Setting at a University Hospital in Oman.

Objective: This study aimed at examining the effectiveness of treating children with autism spectrum disorder (ASD) who present with irritability, aggression, and disruptive behavior at the Sultan Qaboos University Hospital (SQUH) in Muscat, Oman, with risperidone, and to note any sex-based differences among this cohort.

Method: This was a retrospective study conducted at the Department of Behavioral Medicine at SQUH over two years from January 2017 to December 2018. This study included all children aged 3 to 18 years attending the Child and Adolescent Mental Health Service (CAMHS) outpatient clinic with a diagnosis of ASD, based on the DSM-5 criteria, and comorbid disruptive behavior, who had been prescribed risperidone.

Result: This study identified 95 ASD patients (72 males). Male patients' BMI score after 12 months of risperidone treatment showed an increase by 0.62 (1.57 SD; P=0.001); however, there was no significant change among female patients. Somnolence was noted in 69.6% of female patients as compared to 34.7% of males (P=0.003). Among those with a family history of ASD, 5 out of 17 patients had treatment success (29.4%), whereas 70 out of 78 patients (90.0%) who did not have a similar history had successful treatment.

Conclusion: In conclusion, low-dose risperidone monotherapy is effective and well tolerated among some children with ASD who present with disruptive behavior in a naturalistic clinical setting. However, we found that some of the side effects, such as weight gain and somnolence, were concerning.