One in four antipsychotic and antiepileptic drugs prescribed to adults on the autism spectrum are likely inappropriate, according new Australian research.
The study of individuals with autism spectrum disorder found off-label prescribing was high and potentially putting them at risk.
“A particularly interesting and important finding was that a substantial proportion of psychotropic medications given to people were not linked to an approved indication,” study author Dr Rachael Cvejic, lecturer at the department of Developmental Disability Neuropsychiatry, University of New South Wales, said.
As expected, the researchers found that individuals with autism spectrum disorder were much more likely to have a mental health diagnosis than the general population, but even when they took these diagnoses into account, participants were more than four times as likely to be taking potentially inappropriate psychotropic medication than the control group.
In particular, antipsychotics and antiepileptics were commonly prescribed without an indication.
“In these cases, it is likely that antipsychotics (such as risperidone), antiepileptics and propranolol were being used for management of behavioural features, including self-injurious behaviours, irritability and aggression,” they wrote in the paper, published in the British Journal of Psychiatry Open.
The researchers analysed questionnaires completed by 188 adults with autism spectrum disorder and 115 controls about their medical histories, demographics and medications they were taking.
They looked at the individual’s neuropsychiatric profile and the medications prescribed and asked a neuropsychiatrist to determine whether the medications might be appropriate, even if they didn’t strictly adhere to the TGA indication.
More than half of all patients on the autism spectrum were taking one or more psychotropic drugs, compared with around one in five in the control group.
When it came to polypharmacy, more than one in five people with the disorder were taking two or more drugs, compared with one in 23 in the control group.
Dr Cvejic and her team found that stimulants and antipsychotics were the most commonly co-prescribed with other medication classes, often antidepressants.
The researchers found no legitimate indication in the individual’s history for 14.4% of medications prescribed, according to either TGA approval or the expert’s opinion.
“Some of these medications are linked to potentially quite serious side effects,” Dr Cvejic said.
“Considering that, as well as the limited evidence base supporting their efficacy, clinicians need to be weighing up the potential benefits with risk.”
Dr Cvejic said that previous research in people with intellectual disability had shown that medication use tended to increase along with the severity of their disability.
This study underscored the important of ensuring clinicians were aware of the different ways mental health problems could present in patients with autism spectrum disorder, particularly if it was co-occurring with intellectual disability, she said.
The researchers called for greater training for clinicians, both through professional colleges and in the curriculum, to complement already developed resources to help improve care of people on the spectrum.
One element of this was better understanding what a change in behaviour among these patients meant.
“It should prompt a thorough medical and psychiatric assessment to see what could have caused that change in behaviour,” she said.
She said that current clinical guidelines suggested that for the management of behaviours, psychological or behavioural therapies should be considered first-line treatment.
In practice, this was not always done well, she added.
BJPsych Open 2018; online 13 November