Meeting abstract

https://doi.org/10.24869/spsih.2026.348

In the Shadow of a Therapeutic Switch: Dystonic Reactions During Cross-Titration of Atypical Antipsychotics in a Child With Autism Spectrum Disorder – A Case Report

Nina Rančić ; Department of Psychiatry, University Hospital of Split, Spinčićeva 1, 21000 Split, Croatia *
Karla Aleksandra Župa ; Department of Psychiatry, University Hospital of Split, Spinčićeva 1, 21000 Split, Croatia
Ivona Barišić ; Department of Psychiatry, University Hospital of Split, Spinčićeva 1, 21000 Split, Croatia
Anđela Kovačević ; Department of Psychiatry, University Hospital of Split, Spinčićeva 1, 21000 Split, Croatia; Department of Psychiatry, Faculty of Medicine in Rijeka, University of Split, Šoltanska 2, 21000 Split, Croatia
Trpimir Glavina ; Department of Psychiatry, University Hospital of Split, Spinčićeva 1, 21000 Split, Croatia; Department of Psychiatry, Faculty of Medicine in Rijeka, University of Split, Šoltanska 2, 21000 Split, Croatia

* Corresponding author.

Abstract

Autism spectrum disorder (ASD) is characterized
by difficulties in social communication and the
presence of restricted and repetitive patterns of
behavior, interests, and activities. In clinical practice,
psychomotor agitation, irritability, and aggressive
behaviors often require pharmacological
treatment. We present the case of a nine‑year‑old
boy who had been followed for several years on
an outpatient basis by a child and adolescent psychiatrist
with diagnoses of childhood autism and
hyperkinetic disorder. His predominant difficulties were psychomotor agitation, impulsivity, and
problems with emotional regulation, accompanied
by impaired everyday functioning. Because of
these problems, treatment with low-dose aripiprazole
was initiated and gradually titrated. During
follow‑up, a worsening of psychomotor agitation
was observed, and replacement of aripiprazole
with risperidone using a cross‑titration method
was indicated. Several days after risperidone was
introduced, the parents noticed episodes of involuntary
movements lasting a few seconds, characterized
by lateral neck movements in both directions
and generalized body stiffening with elbow
and knee extension, flexion of the hands, and retroflexion
of the neck. The boy had previously exhibited
stereotyped movements, which, together
with his inability to verbally describe symptoms,
made it challenging to distinguish dystonic reactions
from an exacerbation of stereotypies. Due
to suspicion of extrapyramidal side effects, gradual
discontinuation of antipsychotic therapy was
started, and the boy was examined by a child neurologist,
including electroencephalography. The
findings did not point to a neurological basis for
the symptoms, and several weeks after discontinuation
of therapy, the described phenomena completely
resolved. Although the temporal association
between the onset of dystonic reactions and
the period of cross‑titration suggests a possible
role of changes in dopaminergic neurotransmission,
it remains unclear whether they would also
have developed during a sequential switch of antipsychotics.
Pharmacogenetic factors should also
be considered, as CYP2D6 gene variants have been
shown to affect antipsychotic exposure, and more
recent studies in children with ASD indicate that
other genetic variants may influence risperidone
exposure as well. The presented case underscores
the importance of an individualized approach in
the treatment of children with autism spectrum
disorder.

Keywords

autism spectrum disorder; cross‑titration; atypical antipsychotics; dystonic reactions

Hrčak ID:

353114

URI

https://hrcak.srce.hr/353114

Publication date:

15.6.2026.

Article data in other languages: croatian

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