- Risperidone (atypical antipsychotic) may be effective in reducing certain behaviours associated with autism, namely aggression, repetitive behaviour and hyperactivity, though not social functioning and language.
- Fluvoxamine (SSRI antidepressant) may be effective in reducing repetitive thoughts and behaviours, maladaptive behaviours and aggression. Fluvoxamine may also improve language usage, however it does not appear to influence sensorimotor behaviour, sensory response or social relationship to other people. Fluvoxamine is not currently available in New Zealand. It may be a useful addition to the range of medications that are available for people with ASD in this country.
- Haloperidol (typical antipsychotic) may be effective in reducing the overall severity of symptoms of autism as well as specifically reducing irritability and hyperactivity. Haloperidol may be more effective than clomipramine in the treatment of autism, although mean daily doses were lower for clomipramine than those routinely used in New Zealand. Neither drug appears to influence stereotypic behaviour, lethargy or inappropriate speech.
- Naltrexone hydrochloride (opiate antagonist) appears to be ineffective in the short-term. Neither a one-off moderate dose, nor four weeks of low or high-dose naltrexone, had a positive impact on behavioural features of autism or specifically on self-injurious behaviour.
- No major adverse events were reported for any of the interventions assessed in the primary studies. However, these small trials were not designed to determine risk estimates and reliable conclusions about these medications' safety profiles cannot be made.
- Generally speaking, no conclusions could be made about the effectiveness of one class of drug over another, or for the treatment of specific comorbidity.
- The range of drugs considered in the five studies appraised was not representative of the range of pharmacological interventions employed in clinical practice in New Zealand, suggesting that there is a gap in knowledge on many commonly used medications in the management of people with autism.
- Medications are rarely the sole treatment modality for any individuals with autism. As an adjunctive treatment they may be effective with relatively few adverse effects and manageable side effects, although to date evidence is very limited. Larger sampled, double-blind, placebo-controlled trials are required that address the effectiveness and safety of drug interventions for both short and long-term treatment of adolescents and adults with ASD.
- While more research is required on agents that target associated symptoms that interfere with functioning or cause distress, development and evaluation of medications that show promise in treating core symptoms of social and language impairment in ASD should also be a priority.