Paliperidone Palmitate in a Child with Autistic Disorder

Abstract

To the Editor: Autistic disorder (autism) is a neuropsychiatric disorder characterized by impairments in social interaction, communication, and stereotyped behaviors and interests (American Psychiatric Association 2000). Individuals with this disorder often exhibit associated interfering symptoms including irritability, hyperactivity, and inattention. Irritability, defined as aggression, severe tantrums, and self-injury, is a particularly limiting symptom with the capacity to diminish the quality of life for both the affected individual and their caregivers. Historically, antipsychotics have been the pharmacologic treatment of choice for irritability in youth with autism. Early research focused on typical antipsychotics such as haloperidol (Cohen et al. 1980; Anderson et al. 1984). Atypical antipsychotics have a lower rate of side effects such as dyskinesias and are currently considered first-line choice for treatment of irritability associated with autistic disorder (Erickson et al. 2007; Blankenship et al. 2010). Both risperidone and aripiprazole were approved by the U.S. Food and Drug Administration (FDA) to treat irritability in youth with autism aged 5–16 and 6–17 years, respectively. Multiple double-blind, placebo-controlled studies have demonstrated the efficacy of risperidone (Research Units on Pediatric Psychopharmacology Autism 2002; Shea et al. 2004) and aripiprazole (Marcus et al. 2009; Owen et al. 2009) for the treatment of this symptom domain. Paliperidone is the active metabolite of risperidone and was approved by FDA to treat schizophrenia and schizoaffective disorder in adults. Stigler et al. (2010) recently described the effectiveness of paliperidone in treating irritability in two individuals with autism. A 16-year-old female patient and a 20-year-old male patient, both diagnosed with autism, were treated with paliperidone (3 and 12 mg/day, respectively) after they demonstrated a lack of adequate improvement on other medication regimens. Both were judged to have significant improvement in their symptoms, including aggression and tantrums, with paliperidone treatment. No adverse events were reported. Both individuals lost weight and experienced improvements in their fasting lipid profiles while taking paliperidone. In 2009, the FDA approved a sustained-release intramuscular (IM) formulation of paliperidone, paliperidone palmitate, for the treatment of adults with schizophrenia. In this report, we demonstrate the successful use of paliperidone palmitate for the treatment of irritability in a child with autism who was unable to tolerate oral medications.